Multi-level representation of metabolic networks.
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Transcript of Multi-level representation of metabolic networks.
Multi-level representation of metabolic networks
Anna Zhukova 1,2 David J. Sherman 2
1IBGC / University of Bordeaux1 rue Camille Saint-Saens, 33077 Bordeaux cedex France
2Inria / CNRS / University of Bordeauxjoint project-team MAGNOME
351, cours de la Liberation, 33405 Talence cedex France
August 5, 2015
Anna Zhukova Multi-level representation August 5, 2015 1 / 47
Metabolic modeling
Metabolic models are mathematical descriptions of biochemicalreactions between molecules in a cell.
pathway-scale - up to hundreds of reactionsgenome-scale - thousands of reactions
bacterium E. coli [Smallbone, 2013] – 2 168 reactions
yeast S. cerevisiae [Aung et al., 2013] – 2 352 reactions
human [Thiele et al., 2013] – 7 440 reactions
Anna Zhukova Multi-level representation August 5, 2015 2 / 47
Metabolic modeling
Metabolic models are mathematical descriptions of biochemicalreactions between molecules in a cell.
pathway-scale - up to hundreds of reactionsgenome-scale - thousands of reactions
bacterium E. coli [Smallbone, 2013] – 2 168 reactions
yeast S. cerevisiae [Aung et al., 2013] – 2 352 reactions
human [Thiele et al., 2013] – 7 440 reactions
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Precision vs Readability: our solution
Anna Zhukova Multi-level representation August 5, 2015 4 / 47
Introduction
Outline
1 Introduction
2 Generalization method [Zhukova and Sherman, J Comput Biol 2014]
3 Validation [Zhukova and Sherman, J Bioinf Comput Biol 2014]
4 Mimoza: web-based navigation [Zhukova and Sherman, BMC Syst Bio 2015]
5 Conclusions and Perspectives
Anna Zhukova Multi-level representation August 5, 2015 5 / 47
Introduction
Genome-scale models are complicated
Anna Zhukova Multi-level representation August 5, 2015 7 / 47
Introduction
Genome-scale models are complicated
Anna Zhukova Multi-level representation August 5, 2015 7 / 47
Introduction
Self-similarities
3-oxo-fatty acyl-CoAs: different lengths of carbon chains
Anna Zhukova Multi-level representation August 5, 2015 8 / 47
Introduction
Self-similarities
hydroxy fatty acyl-CoAs: different lengths of carbon chains
Anna Zhukova Multi-level representation August 5, 2015 8 / 47
Introduction
Self-similarities
oxidation: hydroxy FA-CoA + NAD↔ 3-oxo-FA-CoA + H+ + NADH
Anna Zhukova Multi-level representation August 5, 2015 8 / 47
Introduction
Objective
exploit self-similaritiessemantically robustmeaningful for biologists
produce abstract viewsessential model structurehighlight the particularitiesexpose potential errors
Anna Zhukova Multi-level representation August 5, 2015 9 / 47
Generalization method
Outline
1 Introduction
2 Generalization method [Zhukova and Sherman, J Comput Biol 2014]
3 Validation [Zhukova and Sherman, J Bioinf Comput Biol 2014]
4 Mimoza: web-based navigation [Zhukova and Sherman, BMC Syst Bio 2015]
5 Conclusions and Perspectives
Anna Zhukova Multi-level representation August 5, 2015 10 / 47
Generalization method
Formal definition: Model
Model: N = 〈M,R〉
- bipartite graph,
Metabolite set: M = {m1, . . . ,mn}
- M-nodes,Ubiq. m. set: M ⊃ Mub
- duplicated M-nodes,
Reaction set: R = {r1, . . . , rk}
- R-nodes,
reaction: R 3 r = 〈M(react),M(prod)〉
- edges bw M- and R-nodes/all the met. are distinct/
/no parallel edges/.
Anna Zhukova Multi-level representation August 5, 2015 11 / 47
Generalization method
Formal definition: Model
Model: N = 〈M,R〉 - bipartite graph,
Metabolite set: M = {m1, . . . ,mn} - M-nodes,
Ubiq. m. set: M ⊃ Mub - duplicated M-nodes,
Reaction set: R = {r1, . . . , rk} - R-nodes,reaction: R 3 r = 〈M(react),M(prod)〉 - edges bw M- and R-nodes
/all the met. are distinct/
/no parallel edges/.
Anna Zhukova Multi-level representation August 5, 2015 11 / 47
Generalization method
Formal definition: Model
Model: N = 〈M,R〉 - bipartite graph,
Metabolite set: M = {m1, . . . ,mn} - M-nodes,Ubiq. m. set: M ⊃ Mub - duplicated M-nodes,
Reaction set: R = {r1, . . . , rk} - R-nodes,reaction: R 3 r = 〈M(react),M(prod)〉 - edges bw M- and R-nodes
/all the met. are distinct/
/no parallel edges/.
Anna Zhukova Multi-level representation August 5, 2015 11 / 47
Generalization method
Formal definition: Model
Model: N = 〈M,R〉 - bipartite graph,
Metabolite set: M = {m1, . . . ,mn} - M-nodes,Ubiq. m. set: M ⊃ Mub - duplicated M-nodes,
Reaction set: R = {r1, . . . , rk} - R-nodes,reaction: R 3 r = 〈M(react),M(prod)〉 - edges bw M- and R-nodes
/all the met. are distinct/ /no parallel edges/.
Anna Zhukova Multi-level representation August 5, 2015 11 / 47
Generalization method
Formal definition: Model
Model: N = 〈M,R〉 - bipartite graph,
Metabolite set: M = {m1, . . . ,mn} - M-nodes,Ubiq. m. set: M ⊃ Mub - duplicated M-nodes,
Reaction set: R = {r1, . . . , rk} - R-nodes,reaction: R 3 r = 〈M(react),M(prod)〉 - edges bw M- and R-nodes
/all the met. are distinct/ /no parallel edges/.
Anna Zhukova Multi-level representation August 5, 2015 11 / 47
Generalization method
Formal definition: Model
Model: N = 〈M,R〉 - bipartite graph,
Metabolite set: M = {m1, . . . ,mn} - M-nodes,Ubiq. m. set: M ⊃ Mub - duplicated M-nodes,
Reaction set: R = {r1, . . . , rk} - R-nodes,reaction: R 3 r = 〈M(react),M(prod)〉 - edges bw M- and R-nodes
/all the met. are distinct/ /no parallel edges/.
Anna Zhukova Multi-level representation August 5, 2015 11 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Metabolite diversity restriction (2): Equivalent metabolites must participatein equivalent reactions. (Min. degrees of gen. M-nodes.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Metabolite diversity restriction (2): Equivalent metabolites must participatein equivalent reactions. (Min. degrees of gen. M-nodes.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Metabolite diversity restriction (2): Equivalent metabolites must participatein equivalent reactions. (Min. degrees of gen. M-nodes.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Metabolite diversity restriction (2): Equivalent metabolites must participatein equivalent reactions. (Min. degrees of gen. M-nodes.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Generalization
Choose equivalence operation ∼:
[m]∼ = {m ∈ M|m ∼ m} - generalized metabolite[m(ub)]
∼= {m(ub)} - (trivial) gen. ub. m.,
[r ]∼ = 〈M([react]),M([prod ])〉= {r |r ∼ r} - generalized reaction
Stoichiomenty preserving restriction (1): All the generalized metabolitesparticipating in a reaction are distinct. (In- and out-degrees of R-nodes areconserved.)
Metabolite diversity restriction (2): Equivalent metabolites must participatein equivalent reactions. (Min. degrees of gen. M-nodes.)
Anna Zhukova Multi-level representation August 5, 2015 12 / 47
Generalization method
Formal definition: Model generalization problem
Problem: Given a metabolic model N = 〈M ⊃ M(ub),R〉 find anequivalence operation ∼ that obeys the stoichiometry preservingrestriction (1) and the metabolite diversity restriction (2), and minimizesthe number of reaction equivalence classes ]R/ ∼.
N/ ∼ = 〈M/ ∼,R/ ∼〉 - generalized model,M/ ∼ = {[m1]∼, . . . , [mn]∼} - generalized metabolite set,R/ ∼ = {[r1]∼, . . . , [rk ]∼} - generalized reaction set.
Anna Zhukova Multi-level representation August 5, 2015 13 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
[m(ub)]∼ = {m(ub)} - gen. ub. m.,
[m]∼ = M\M(ub) - gen. met.
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
[m(ub)]∼ = {m(ub)} - gen. ub. m.,
[m]∼ = M\M(ub) - gen. met.
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
Metabolite ontology – partial order of M-nodes
[de Matos et al., 2010]
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
Metabolite ontology – partial order of M-nodes
Exact set cover (NP-complete [Goldreich, 2008])Greedy alg. – best polyn. time approx. [Feige, 1998]
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
Metabolite ontology – partial order of M-nodes
Exact set cover (NP-complete [Goldreich, 2008])Greedy alg. – best polyn. time approx. [Feige, 1998]
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Model generalization algorithm
Algorithm:
1 Define ∼;
2 Satisfy restriction (1);
3 Satisfy restriction (2);
Anna Zhukova Multi-level representation August 5, 2015 14 / 47
Generalization method
Peroxisome of Y. lipolytica: 66→ 17 reactions
Anna Zhukova Multi-level representation August 5, 2015 15 / 47
Generalization method
Using ChEBI for model generalization
Anna Zhukova Multi-level representation August 5, 2015 16 / 47
Generalization method
Using ChEBI for model generalization
Anna Zhukova Multi-level representation August 5, 2015 16 / 47
Generalization method
Using ChEBI for model generalization
Anna Zhukova Multi-level representation August 5, 2015 16 / 47
Generalization method
Using ChEBI for model generalization
Anna Zhukova Multi-level representation August 5, 2015 16 / 47
Generalization method
Using ChEBI for model generalization
Anna Zhukova Multi-level representation August 5, 2015 16 / 47
Generalization method
Using ChEBI for model generalization
Anna Zhukova Multi-level representation August 5, 2015 16 / 47
Generalization method
What hinders generalization?
Missing ChEBI annotationsMissing relationships in ChEBIPseudoreactions
Anna Zhukova Multi-level representation August 5, 2015 17 / 47
Generalization method
What hinders generalization?
Missing ChEBI annotationsMissing relationships in ChEBIPseudoreactions
Anna Zhukova Multi-level representation August 5, 2015 17 / 47
Generalization method
Model generalization library
download frommetamogen.gforge.inria.fr
input: SBML model
output: 2 SBML models:1 initial model + groups extension:
group of ub. metabolitesgroups of equiv. metabolitesgroups of equiv. reactions
2 generalized model
implemented in Python
Anna Zhukova Multi-level representation August 5, 2015 18 / 47
Generalization method
Model generalization library
download frommetamogen.gforge.inria.fr
input: SBML model
output: 2 SBML models:1 initial model + groups extension:
group of ub. metabolitesgroups of equiv. metabolitesgroups of equiv. reactions
2 generalized model
implemented in Python
Anna Zhukova Multi-level representation August 5, 2015 18 / 47
Validation
Outline
1 Introduction
2 Generalization method [Zhukova and Sherman, J Comput Biol 2014]
3 Validation [Zhukova and Sherman, J Bioinf Comput Biol 2014]
4 Mimoza: web-based navigation [Zhukova and Sherman, BMC Syst Bio 2015]
5 Conclusions and Perspectives
Anna Zhukova Multi-level representation August 5, 2015 19 / 47
Validation
Validation set-up
Goal: Mathematically the generalization method is correct. But is ituseful for biologists?
Path2Models [Buchel et al., 2013]
KEGG [Kanehisa et al., 2012]→ SBML [Hucka et al., 2003]non-curated
1 286 metabolic networksmapped to the NCBI taxonomy database [Sayers et al., 2009]
138 eukaryota1 045 bacteria103 archaea
β−oxidation of fatty acids
Anna Zhukova Multi-level representation August 5, 2015 20 / 47
Validation
β−oxidation of fatty acids
1 dehydraton: fatty acyl-CoA (n)→dehydroacyl-CoA
2 hydration: dehydroacyl-CoA→hydroxyacyl-CoA
3 oxidation: hydroxyacyl-CoA→3-ketoacyl-CoA
4 thiolysis: 3-ketoacyl-CoA→fatty acyl-CoA (n-2) + acetyl-CoA
Anna Zhukova Multi-level representation August 5, 2015 21 / 47
Validation
β−oxidation of fatty acids
1 dehydraton: fatty acyl-CoA (n)→dehydroacyl-CoA
2 hydration: dehydroacyl-CoA→hydroxyacyl-CoA
3 oxidation: hydroxyacyl-CoA→3-ketoacyl-CoA
4 thiolysis: 3-ketoacyl-CoA→fatty acyl-CoA (n-2) + acetyl-CoA
Anna Zhukova Multi-level representation August 5, 2015 21 / 47
Validation
β−oxidation of fatty acids
Anna Zhukova Multi-level representation August 5, 2015 21 / 47
Validation
Configurations
Expected Alternative paths
Broken cycles
Anna Zhukova Multi-level representation August 5, 2015 22 / 47
Validation
Results
β-oxidation % ofcycle configuration all networks eukaryota bacteria archaea
complete cycle 10% 3% 11% 0%one step missing 10% 25% 7% 18%two steps missing 11% 12% 10% 24%
three steps missing 50% 57% 49% 58%all steps missing 19% 3% 23% 0%
Archaea:
gene candidates for degradation of fatty acids via β-oxidation
do not encode components of a fatty acid synthase complex[Falb et al., 2008].
Anna Zhukova Multi-level representation August 5, 2015 23 / 47
Validation
Results
β-oxidation % ofcycle configuration all networks eukaryota bacteria archaea
complete cycle 10% 3% 11% 0%one step missing 10% 25% 7% 18%two steps missing 11% 12% 10% 24%
three steps missing 50% 57% 49% 58%all steps missing 19% 3% 23% 0%
Archaea:
gene candidates for degradation of fatty acids via β-oxidation
do not encode components of a fatty acid synthase complex[Falb et al., 2008].
Anna Zhukova Multi-level representation August 5, 2015 23 / 47
Validation
One missing step
128 (10%) gen. networks miss 1 step:
1 dehydraton: 23 (18%)
2 hydration: 8 (6,2%)
3 oxidation: 95 (74,2%)
4 thiolysis: 2 (1,6%)
Systematic error in Path2Models?
Y. lipolytica (strain CLIB 122/E 150):
BMID000000136479– no oxidation
MODEL1111190000 (curated)[Loira et al., 2012] – complete cycle
Anna Zhukova Multi-level representation August 5, 2015 24 / 47
Validation
One missing step
128 (10%) gen. networks miss 1 step:
1 dehydraton: 23 (18%)
2 hydration: 8 (6,2%)
3 oxidation: 95 (74,2%)
4 thiolysis: 2 (1,6%)
Systematic error in Path2Models?
Y. lipolytica (strain CLIB 122/E 150):
BMID000000136479– no oxidation
MODEL1111190000 (curated)[Loira et al., 2012] – complete cycle
Anna Zhukova Multi-level representation August 5, 2015 24 / 47
Validation
One missing step
128 (10%) gen. networks miss 1 step:
1 dehydraton: 23 (18%)
2 hydration: 8 (6,2%)
3 oxidation: 95 (74,2%)
4 thiolysis: 2 (1,6%)
Systematic error in Path2Models?
Y. lipolytica (strain CLIB 122/E 150):
BMID000000136479– no oxidation
MODEL1111190000 (curated)[Loira et al., 2012] – complete cycle
Anna Zhukova Multi-level representation August 5, 2015 24 / 47
Validation
Generalization is validated
Generalization is useful to:understand, compare and classify networks,detect general network structure,highlight possible problems,detect organism-specific particularities.
Anna Zhukova Multi-level representation August 5, 2015 25 / 47
Mimoza
Outline
1 Introduction
2 Generalization method [Zhukova and Sherman, J Comput Biol 2014]
3 Validation [Zhukova and Sherman, J Bioinf Comput Biol 2014]
4 Mimoza: web-based navigation [Zhukova and Sherman, BMC Syst Bio 2015]
5 Conclusions and Perspectives
Anna Zhukova Multi-level representation August 5, 2015 26 / 47
Mimoza
Visualization requirements
users’ models as an input
desktop? online?
zooming user interface (ZUI)!
decomposition into modulescompartmentsgeneralized elements
Anna Zhukova Multi-level representation August 5, 2015 28 / 47
Mimoza
Visualization requirements
users’ models as an inputdesktop? online?
zooming user interface (ZUI)!decomposition into modules
compartmentsgeneralized elements
JWS online [Snoep et al., 2003]
Anna Zhukova Multi-level representation August 5, 2015 28 / 47
Mimoza
Visualization requirements
users’ models as an inputdesktop? online?
zooming user interface (ZUI)!decomposition into modules
compartmentsgeneralized elements
CellDesigner [Funahashi et al., 2008]
Anna Zhukova Multi-level representation August 5, 2015 28 / 47
Mimoza
Visualization requirements
users’ models as an inputdesktop? online?zooming user interface (ZUI)!
geometric zoom
semantic zoomdecomposition into modules
compartmentsgeneralized elements
Anna Zhukova Multi-level representation August 5, 2015 28 / 47
Mimoza
Visualization requirements
users’ models as an inputdesktop? online?zooming user interface (ZUI)!
geometric zoom
semantic zoomdecomposition into modules
compartmentsgeneralized elements
Anna Zhukova Multi-level representation August 5, 2015 28 / 47
Mimoza
Visualization requirements
users’ models as an inputdesktop? online?zooming user interface (ZUI)!
geometric zoomsemantic zoom
decomposition into modulescompartmentsgeneralized elements
Anna Zhukova Multi-level representation August 5, 2015 28 / 47
Mimoza
Visualization requirements
users’ models as an inputdesktop? online?zooming user interface (ZUI)!decomposition into modules
compartmentsgeneralized elements
Anna Zhukova Multi-level representation August 5, 2015 28 / 47
Mimoza
http://mimoza.bordeaux.inria.fr/
Anna Zhukova Multi-level representation August 5, 2015 29 / 47
Mimoza
Mimoza
3-level model representation:1 full model2 generalized view3 compartment view
Anna Zhukova Multi-level representation August 5, 2015 30 / 47
Mimoza
Mimoza
3-level model representation:1 full model2 generalized view3 compartment view
Anna Zhukova Multi-level representation August 5, 2015 30 / 47
Mimoza
Mimoza
3-level model representation:1 full model2 generalized view3 compartment view
Anna Zhukova Multi-level representation August 5, 2015 30 / 47
Mimoza
Comparison to other tools
Tool Imposed Semantic User’s Automaticname layout zoom model layout Modules
Genome yes no no - noProjector
if created if createdCellular yes no no - no
Overview
Reactome yes/no yes no - yes
NaviCell no by user yes no by user
Mimoza no yes yes yes yes
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Mimoza
Pipeline
1 user submits a model in SBML format2 model generalization (if needed)3 layout of the network graph4 rendering into a zoomable interactive map5 the result can be browsed online or downloaded
mimoza.bordeaux.inria.fr
Anna Zhukova Multi-level representation August 5, 2015 32 / 47
Mimoza
Implementation details
Python + libSBML [Bornstein et el., 2008] + libsbgnpy [Konig] – libraryModel generalization [Zhukova and Sherman, 2014] – modulesthe Gene Ontology [Ashburner et al., 2000] – compartments’ nestingTulip library [Auber, 2004] – graph layoutLeaflet [leafletjs.com] + GeoJSON [geojson.org] – ZUIJavascript, JQuery – on-line
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Mimoza
Layers layoutGeneralized model layout
Full model layout – challenge ofcorrespondence
Anna Zhukova Multi-level representation August 5, 2015 34 / 47
Mimoza
Layers layoutGeneralized model layoutA combination of Tulip [Auber, 2004]algorithms:
1 split into connected components2 apply a layout algorithm
no cycles=⇒ Hierarchical Layout≤ 3 cycles & ≤ 100 nodes=⇒ Circular Layout
otherwise=⇒ Force-Directed Layout
3 combine back together withConnected Comp. Packing
Anna Zhukova Multi-level representation August 5, 2015 34 / 47
Mimoza
Layers layoutGeneralized model layoutA combination of Tulip [Auber, 2004]algorithms:
1 split into connected components2 apply a layout algorithm
no cycles=⇒ Hierarchical Layout≤ 3 cycles & ≤ 100 nodes=⇒ Circular Layout
otherwise=⇒ Force-Directed Layout
3 combine back together withConnected Comp. Packing
Anna Zhukova Multi-level representation August 5, 2015 34 / 47
Mimoza
Layers layoutGeneralized model layout
Full model layout – challenge ofcorrespondence
keep coordinates fornon-generalized elementsconserve the colorsgeneralized elements are largersimilar metabolites/reactions –next to each other inside thegeneralized element
Anna Zhukova Multi-level representation August 5, 2015 34 / 47
Mimoza
Layers layoutGeneralized model layout
Full model layout – challenge ofcorrespondence
Serialization of layout
SBML with layout extension[Gauges et al., 2013] – import/exportSBGN-ML [Le Novere et al., 2009]– export
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Mimoza
Technical details
GeoJSON [geojson.org]
Leaflet [leafletjs.com]
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Mimoza
Technical details
GeoJSON [geojson.org]
Leaflet [leafletjs.com]
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Mimoza
Technical details
GeoJSON [geojson.org]
Leaflet [leafletjs.com]
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Mimoza
Download and distribution
as a standalone application on the Mimoza web server:mimoza.bordeaux.inria.fr
download the result as a COMBINE Archive [Bergmann et al., 2014]
embed a Mimoza view in another web-pagedownload the Mimoza source code
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Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
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Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
Anna Zhukova Multi-level representation August 5, 2015 37 / 47
Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
Anna Zhukova Multi-level representation August 5, 2015 37 / 47
Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
Anna Zhukova Multi-level representation August 5, 2015 37 / 47
Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
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Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
Anna Zhukova Multi-level representation August 5, 2015 37 / 47
Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
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Mimoza
Genome-scale model: yeast7 [Aung et al., 2003]
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Conclusions and Perspectives
Outline
1 Introduction
2 Generalization method [Zhukova and Sherman, J Comput Biol 2014]
3 Validation [Zhukova and Sherman, J Bioinf Comput Biol 2014]
4 Mimoza: web-based navigation [Zhukova and Sherman, BMC Syst Bio 2015]
5 Conclusions and Perspectives
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Conclusions and Perspectives
Summary
Generalization method
Mimoza
Validation
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Conclusions and Perspectives
Summary
Generalization method
Mimoza
Validation
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Conclusions and Perspectives
Summary
Generalization method Mimoza
Validation
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Conclusions and Perspectives
Compressing bipartite graphs with repetitions
Generalization for metabolic networks :metabolite grouping - ChEBIreaction grouping - repetitive patterns:reactions with equiv. reactants/products
Generalized model :one representative element per patternminimizes number of generalized reactionspreserves reaction stoichiometriesobeys metabolite diversity constraint
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Conclusions and Perspectives
Compressing bipartite graphs with repetitions
Generalization for metabolic networks :metabolite grouping - ChEBIreaction grouping - repetitive patterns:reactions with equiv. reactants/products
Generalized model :one representative element per patternminimizes number of generalized reactionspreserves reaction stoichiometriesobeys metabolite diversity constraint
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Conclusions and Perspectives
Compressing bipartite graphs with repetitions
Generalization for metabolic networks bipartite graphs:metabolite M-node grouping - ChEBI partial orderreaction R-node grouping - repetitive patterns:reactions R-nodes with equiv. reactants/products in-/out-degrees
Generalized model Compressed graph:one representative element per patternminimizes number of generalized reactions R-nodespreserves reaction stoichiometries in-/out- degrees of R-nodesobeys metabolite diversity constraint minim. M-node degrees
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Conclusions and Perspectives
Finding template models for model inference
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Conclusions and Perspectives
Finding template models for model inference
Pantograph toolbox [Loira et al., 2015]
orthologytemplate model
details vs generalitymodel for a related organism
generalized modelcollective generalizations as templates:
several close speciesseveral partial models
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Conclusions and Perspectives
Finding template models for model inference
Pantograph toolbox [Loira et al., 2015]
orthologytemplate model
details vs generalitymodel for a related organismgeneralized model
collective generalizations as templates:several close speciesseveral partial models
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Conclusions and Perspectives
Finding template models for model inference
Pantograph toolbox [Loira et al., 2015]
orthologytemplate model
details vs generalitymodel for a related organismgeneralized modelcollective generalizations as templates:
several close speciesseveral partial models
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Conclusions and Perspectives
Finding template models for model inference
Pantograph toolbox [Loira et al., 2015] – required updatetemplate reaction→ (at most) one target reaction
generalized template reaction→ (up to) several similar targetreactions
reaction specification methodcollective generalizations with flat met. ontology - model merge
numbers of factored reactionsas weights
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Conclusions and Perspectives
Finding template models for model inference
Pantograph toolbox [Loira et al., 2015] – required updatetemplate reaction→ (at most) one target reactiongeneralized template reaction→ (up to) several similar targetreactions
reaction specification method
collective generalizations with flat met. ontology - model mergenumbers of factored reactionsas weights
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Conclusions and Perspectives
Finding template models for model inference
Pantograph toolbox [Loira et al., 2015] – required updatetemplate reaction→ (at most) one target reactiongeneralized template reaction→ (up to) several similar targetreactions
reaction specification methodcollective generalizations with flat met. ontology - model merge
numbers of factored reactionsas weights
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Conclusions and Perspectives
Classifying related metabolisms
Taxonomy (systematics) is the science of biological classification.Genomic methods - based on mutations in orthologous genes[Olsen, 1994]
Metabolic taxonomy - based on:substrate-product relationships [Chang 2011]metabolic pathways [Hong, 2004; Mazurie, 2008]enzyme information [Ma, 2004]
model generalizationcollective generalizationintersection of conserved partsorganism-specific adaptations
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Conclusions and Perspectives
Classifying related metabolisms
Taxonomy (systematics) is the science of biological classification.Genomic methods - based on mutations in orthologous genes[Olsen, 1994]
Metabolic taxonomy - based on:substrate-product relationships [Chang 2011]metabolic pathways [Hong, 2004; Mazurie, 2008]enzyme information [Ma, 2004]model generalization
collective generalizationintersection of conserved partsorganism-specific adaptations
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Conclusions and Perspectives
Classifying reactions in reaction databases
Rhea [Morgat et al., 2015], BioPath [Reitz et al., 2004], KEGG reaction[Kanehisa et al., 2012], MetaCyC [Caspi et al., 2012]
involved metabolitesreversibilitycatalyzing enzymespathwayscross references
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Conclusions and Perspectives
Classifying reactions in reaction databases
Rhea [Morgat et al., 2015]
manually annotatedmetabolites associated to ChEBI (compatible with ourgeneralization)
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Conclusions and Perspectives
Classifying reactions in reaction databases
Generalization of RhEA =⇒ reaction hierarchy
3 applications of model generalization:
1 database-wide stoichiometry constraints
most specificcompatible with any modeldirect ancestors
2 reaction group-wide stoich. constraints
most generalroot ancestors
3 model-wide stoichiometry constraints
compatible with the modelintermediate ancestors
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Conclusions and Perspectives
Classifying reactions in reaction databases
Generalization of RhEA =⇒ reaction hierarchy
3 applications of model generalization:
1 database-wide stoichiometry constraints
most specificcompatible with any modeldirect ancestors
2 reaction group-wide stoich. constraints
most generalroot ancestors
3 model-wide stoichiometry constraints
compatible with the modelintermediate ancestors
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Conclusions and Perspectives
Classifying reactions in reaction databases
Generalization of RhEA =⇒ reaction hierarchy
3 applications of model generalization:
1 database-wide stoichiometry constraints
most specificcompatible with any modeldirect ancestors
2 reaction group-wide stoich. constraints
most generalroot ancestors
3 model-wide stoichiometry constraints
compatible with the modelintermediate ancestors
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Conclusions and Perspectives
Classifying reactions in reaction databases
Generalization of RhEA =⇒ reaction hierarchy
3 applications of model generalization:
1 database-wide stoichiometry constraints
most specificcompatible with any modeldirect ancestors
2 reaction group-wide stoich. constraints
most generalroot ancestors
3 model-wide stoichiometry constraints
compatible with the modelintermediate ancestors
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Conclusions and Perspectives
Suggesting extensions to ChEBI
Relaxed
Model generalization methodMetabolite grouping based on:
relationships in ChEBIno ChEBI annotation =⇒ no generalization
similar reactionsReaction grouping based on
fuzzy
keys:specific reactants/products
- numbers
generalized - ancestor ChEBI idsnot generalized - ids
ubiquitous reactants/products - ids
Constraints
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Conclusions and Perspectives
Suggesting extensions to ChEBI
Relaxed Model generalization methodMetabolite grouping based on:
relationships in ChEBI – predict them if neededno ChEBI annotation =⇒ no generalization
similar reactionsReaction grouping based on fuzzy keys:
specific reactants/products - numbersgeneralized reactants - ancestor ChEBI idsnot gen. reactants - ids
ubiquitous reactants/products - ids
Constraints
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Conclusions and Perspectives
Acknowledgements
MAGNOME,Inria-Bordeaux
David J ShermanRogrigo AssarPascal DurrensWitold DyrkaXavier CalcasJoaquin FernandezAnne-Laure GautierNatalia GolenetskayaRazanne IssaFlorian LajusNicolas Loira
l’Institut Micalis,INRA-Grignon
Stephanie MichelyCecile NeuvegliseJean-Marc Nicaud
MABioVis,LaBRI, Bordeaux
Romain BourquiAntoine Lambert
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