Hsp104-dependent ability to assimilate mannitol and sorbitol conferred by a truncated Cyc8 with a C-terminal polyglutamine in Saccharomyces cerevisiae

• Published in: PloS one 2020-11, Vol.15 (11), p.e0242054-e0242054
• Main Authors: Tanaka, Hideki, Murata, Kousaku, Hashimoto, Wataru, Kawai, Shigeyuki
• Format: Article
• Language: English
• Subjects: Amino acids; Analysis; Assimilation; Binding sites; Biology and Life Sciences; Biotechnology; Carbon; Codon, Nonsense; D-Sorbitol; Dehydrogenases; Deoxyribonucleic acid; DNA; Food science; Gene Expression Regulation, Fungal; Genotype & phenotype; Glucose; Glutamine; Glycerol; Guanidine hydrochloride; Heat-Shock Proteins - metabolism; Influence; Laboratories; Mannitol; Mannitol - metabolism; Mutation; Nuclear Proteins - genetics; Peptides - metabolism; Physical Sciences; Physiological aspects; Plasmids; Polyglutamine; Polyols; Promoter Regions, Genetic; Protein Domains; Proteins; Repressor Proteins - chemistry; Repressor Proteins - genetics; Repressor Proteins - metabolism; Research and Analysis Methods; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Sorbitol; Sorbitol - metabolism; Transcription; Trinucleotide repeat diseases; Yeast; Yeasts
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0242054

Tup1-Cyc8 (also known as Tup1-Ssn6) is a general transcriptional corepressor. D-Mannitol (mannitol) and D-sorbitol (sorbitol) are the major polyols in nature. Budding yeast Saccharomyces cerevisiae is unable to assimilate mannitol or sorbitol, but acquires the ability to assimilate mannitol due to a spontaneous mutation in TUP1 or CYC8. In this study, we found that spontaneous mutation of TUP1 or CYC8 also permitted assimilation of sorbitol. Some spontaneous nonsense mutations of CYC8 produced a truncated Cyc8 with a C-terminal polyglutamine. The effects were guanidine hydrochloride-sensitive and were dependent on Hsp104, but were complemented by introduction of CYC8, ruling out involvement of a prion. Assimilation of mannitol and sorbitol conferred by other mutations of TUP1 or CYC8 was guanidine hydrochloride-tolerant. It is physiologically reasonable that S. cerevisiae carries this mechanism to acquire the ability to assimilate major polyols in nature.