AP2/EREBP Transcription Factor Family Garen and Joanna.
-
Upload
claire-holt -
Category
Documents
-
view
215 -
download
3
Transcript of AP2/EREBP Transcription Factor Family Garen and Joanna.
AP2/EREBP Transcription Factor Family
Garen and Joanna
Transcription Factors
Transcription Factors (TF) are proteins that regulate the transcription of genes
Three general categories of TFs Bind to RNA Polymerase Bind to another TF Bind to specific DNA sequences
Most bind upstream of the target gene in the promoter sequence
What is AP2?
AP2 derives name from APETALA2 protein Domain sequence of 70 amino acids
Unique to Plants Contain either 1 or 2 AP2 Domains
EREBP and AP2 subfamilies Present during many stages of plant
development in all organs Our focus is seed development
3 Types of AP2 Proteins
Three classes of single AP2 repeat proteins Ethylene Response Elements Binding Proteins
(EREBPs) Dehydration Response Elements (DREs) RAV1 and RAV2
Sub-families of AP2
Sub-family EREBP RAV DRE
Binding
Sequence
TAAGAGCCG
CC CAACA+
CACCTG
[ag]CCGAC
What is its role in plants?
Are involved in various aspects of plant growth and development Flower Development Hormone signal transduction Cellular Differentiation
Responds to biotic and abiotic stresses Drought (DREs) Low Temperature Pathogens
More specifically…
Certain AP2 genes control seed mass and seed size in Arabidopsis.
May negatively affect gibberellin activity in regulating cell size and number during seed development
Large seed size correlates with deformed flowers
Mechanisms
Seed size affected two different ways when AP2-10 is non-functional
1) Seed cavity size enlarged This allows for extended growth of
cotyledons
2) Prolonged mitotic activity after torpedo stage leads results in extended growth of embryo
Wildtype Seed
Wildtype Seed Coat
Mutant Seed
Mutant Seed Coat
Conclusion
AP2 transcription factors are crucial to many plant processes
Its effects on seed development may have significant repercussions in other organs, as exemplified by deformed flowers
Masking? There’s still much we don’t know, but the
research continues