Identification of the residues in the Myb domain of maize C1 that specify the interaction with the bHLH cofactor R.

Proc Natl Acad Sci U S A

Department of Plant Biology and Plant Biotechnology Center, Ohio State University, Columbus, OH 43210, USA. 1Wosu.edu

Published: December 2000

AI Article Synopsis

Article Abstract

The maize Myb transcription factor C1 depends on the basic helix-loop-helix (bHLH) proteins R or B for regulatory function, but the closely related Myb protein P does not. We have used the similarity between the Myb domains of C1 and P to identify residues that specify the interaction between the Myb domain of C1 and the N-terminal region of R. Substitution of four predicted solvent-exposed residues in the first helix of the second Myb repeat of P with corresponding residues from C1 is sufficient to confer on P the ability to physically interact with R. However, two additional Myb domain amino acid changes are needed to make the P regulatory activity partially dependent on R in maize cells. Interestingly, when P is altered so that it interacts with R, it can activate the Bz1 promoter, normally regulated by C1 + R but not by P. Together, these findings demonstrate that the change of a few amino acids within highly similar Myb domains can mediate differential interactions with a transcriptional coregulator that plays a central role in the regulatory specificity of C1, and that Myb domains play important roles in combinatorial transcriptional regulation.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC17618PMC
http://dx.doi.org/10.1073/pnas.250379897DOI Listing

Publication Analysis

Top Keywords

myb domain
12
myb domains
12
myb
9
identification residues
4
residues myb
4
domain maize
4
maize interaction
4
interaction bhlh
4
bhlh cofactor
4
cofactor maize
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!