Physical interactions between ABA response loci of Arabidopsis

Nakamura, S Lynch, TJ Finkelstein, RR

S. Nakamura et al., Physical interactions between ABA response loci of Arabidopsis, PLANT J, 26(6), 2001, pp. 627-635

34

INGLESE

Article

Plant Sciences","Animal & Plant Sciences

PLANT JOURNAL

0960-7412 → ACNP

26

6

2001

627 - 635

ISI

0960-7412(200106)26:6<627:PIBARL>2.0.ZU;2-S

Genetic and physiological studies have shown that the Arabidopsis thaliana abscisic acid-insensitive (ABi) loci interact to regulate seed-specific and /or ABA-inducible gene expression. We have used the yeast two-hybrid assay to determine whether any of these genetic interactions reflect direct physi cal interactions. By this criterion, only ABI3 and ABI5 physically interact with each other, and ABI5 can form homodimers. The B1 domain of ABI3 is es sential for this interaction; this is the first specific function ascribed to this domain of the ABI3/VP1 family. The ABI5 domains required for intera ction with ABI3 include two conserved charged domains in the amino-terminal half of the protein. An additional conserved charged domain appears to hav e intrinsic transcription activation function in this assay. Yeast one-hybr id assays with a lacZ reporter gene under control of the late embryogenesis -abundant AtEm6 promoter show that only ABI5 binds directly to this promote r fragment.