Functional Dissection of the Global Repressor Tup1 in Yeast: Dominant Role of the C-Terminal Repression Domain

Corresponding author: Robert J. Trumbly, Medical College of Ohio, 3035 Arlington Ave., Toledo, OH 43614-5804., rtrumbly{at}mco.edu (E-mail)

Communicating editor: M. HAMPSEY

In the yeast Saccharomyces cerevisiae, Tup1, in association with Cyc8 (Ssn6), functions as a general repressor of transcription. Tup1 and Cyc8 are required for repression of diverse families of genes coordinately controlled by glucose repression, mating type, and other mechanisms. This repression is mediated by recruitment of the Cyc8-Tup1 complex to target promoters by sequence-specific DNA-binding proteins. We created a library of XhoI linker insertions and internal in-frame deletion mutations within the TUP1 coding region. Insertion mutations outside of the WD domains were wild type, while insertions within the WD domains induced mutant phenotypes with differential effects on the target genes SUC2, MFA2, RNR2, and HEM13. Deletion mutations confirmed previous findings of two separate repression domains in the N and C termini. The cumulative data suggest that the C-terminal repression domain, located near the first WD repeat, plays the dominant role in repression. Although the N-terminal repression domain is sufficient for partial repression, deletion of this region does not compromise repression. Surprisingly, deletion of the majority of the histone-binding domain of Tup1 also does not significantly reduce repression. The N-terminal region containing potential -helical coiled coils is required for Tup1 oligomerization and association with Cyc8. Association with Cyc8 is required for repression of SUC2, HEM13, and RNR2 but not MFA2 and STE2.

This article has been cited by other articles:

				K. W. Mulder, G. S. Winkler, and H. Th. M. Timmers DNA damage and replication stress induced transcription of RNR genes is dependent on the Ccr4-Not complex Nucleic Acids Res., November 7, 2005; 33(19): 6384 - 6392. [Abstract] [Full Text] [PDF]

				R A Sporici, J S Hodskins, D M Locasto, L B Meszaros, A L Ferry, A M Weidner, C A Rinehart, J C Bailey, I M Mains, and S E Diamond Repression of the prolactin promoter: a functional consequence of the heterodimerization between Pit-1 and Pit-1 {beta} J. Mol. Endocrinol., October 1, 2005; 35(2): 317 - 331. [Abstract] [Full Text] [PDF]

				S. R. Green and A. D. Johnson Genome-wide Analysis of the Functions of a Conserved Surface on the Corepressor Tup1 Mol. Biol. Cell, June 1, 2005; 16(6): 2605 - 2613. [Abstract] [Full Text] [PDF]

				F. Fagerstrom-Billai and A. P. H. Wright Functional Comparison of the Tup11 and Tup12 Transcriptional Corepressors in Fission Yeast Mol. Cell. Biol., January 15, 2005; 25(2): 716 - 727. [Abstract] [Full Text] [PDF]

				S. R. Green and A. D. Johnson Promoter-dependent Roles for the Srb10 Cyclin-dependent Kinase and the Hda1 Deacetylase in Tup1-mediated Repression in Saccharomyces cerevisiae Mol. Biol. Cell, September 1, 2004; 15(9): 4191 - 4202. [Abstract] [Full Text] [PDF]

				H. Song, P. Hasson, Z. Paroush, and A. J. Courey Groucho Oligomerization Is Required for Repression In Vivo Mol. Cell. Biol., May 15, 2004; 24(10): 4341 - 4350. [Abstract] [Full Text] [PDF]