Functional Comparison of the Tup11 and Tup12 Transcriptional Corepressors in Fission Yeast

Abstract

Gene duplication is considered an important evolutionary mechanism. Unlike many characterized species, the fission yeast ؊ mutants and are over-represented in genes that have previously been shown to respond to a range of different stress conditions. Genes specifically derepressed in tup12 ؊ mutants require the Ssn6 protein for their repression. As for Tup12, Ssn6 is also required for efficient adaptation to KCl-and CaCl 2 -mediated stress. We conclude that Tup11 and Tup12 are at least partly functionally diverged and suggest that the Tup12 and Ssn6 proteins have adopted a specific role in regulation of the stress response.

Individual Subunits of the Ssn6-Tup11/12 Corepressor Are Selectively Required for Repression of Different Target Genes

“…The individual genes identified in each of these experiments are listed in Table S1 in the supplemental material. Several genes showing altered expression in each of these DNA microarray studies have been studied independently by RT-PCR under the same conditions (data not shown) (13). In general, the results were in good agreement with the DNA microarray results.…”

“…1A), similar to that observed for Tup11 and Tup12 previously (13). To analyze the function of Ssn6, we created a diploid strain containing a heterozygous null allele of the ssn6 gene by insertion of a kanamycin cassette.…”

“…Kanamycin (200 mg/liter) was added to rich media 75, and 5-flouroorotic acid (5-FOA, 0.1%) was added to MMuracil media after autoclaving. All extractions for immunoprecipitation and microarray analysis were made from cells grown in rich media except where selection for plasmids was appropriate (13).…”

“…In the fission yeast, Schizosaccharomyces pombe, there are two paralogous TUP1-like genes encoding the Tup11 and Tup12 proteins (18,24,32). Tup11 and Tup12 have some redundant functions (18,24), but there is also a clear difference in the roles of Tup11 and Tup12 in stress responses (13). Tup11 and Tup12 can interact with each other and with the S. pombe Ssn6 protein (13), but it is not clear whether they coexist in individual corepressor complexes or whether they participate in distinct corepressor pools that are recruited to overlapping but distinct sets of genes.…”

Molecular cloning and characterization of WdTUP1, a gene that encodes a potential transcriptional repressor important for yeast-hyphal transitions in Wangiella (Exophiala) dermatitidis

“…Molecular and biochemical studies document that a Tup1p has three functionally defined domains: an N-terminal domain involved in interactions with Ssn6p (Carrico and Zitomer, 1998;Zhang et al, 2002), a C-terminal seven repeated WD40 domain important for protein interactions and tetramerization (Sprague et al, 2000), and a central domain required for the repression activity of the complex (FagerstromBillai and Wright, 2005;Tzamarias and Struhl, 1994). In spite of their similar structures, repressions of target genes by Tup1 proteins are reported to occur by different molecular mechanisms (Fagerstrom-Billai and Wright, 2005).…”