PMID:15728580

Citation	Gemmill, TR, Wu, X and Hanes, SD (2005) Vanishingly low levels of Ess1 prolyl-isomerase activity are sufficient for growth in Saccharomyces cerevisiae. J. Biol. Chem. 280:15510-7
Abstract	Ess1 is an essential peptidylprolyl-cis/trans-isomerase in the yeast Saccharomyces cerevisiae. Ess1 and its human homolog, Pin1, bind to phospho-Ser-Pro sites within proteins, including the carboxyl-terminal domain (CTD) of Rpb1, the largest subunit of RNA polymerase II (pol II). Ess1 and Pin1 are thought to control mRNA synthesis by catalyzing conformational changes in Rpb1 that affect interaction of cofactors with the pol II transcription complex. Here we have characterized wild-type and mutant Ess1 proteins in vitro and in vivo. We found that Ess1 preferentially binds and isomerizes CTD heptad-repeat (YSPTSPS) peptides that are phosphorylated on Ser5. Binding by the mutant proteins in vitro was essentially normal, and the proteins were largely stable in vivo. However, their catalytic activities were reduced >1,000-fold. These data along with results of in vivo titration experiments indicate that Ess1 isomerase activity is required for growth, but only at vanishingly low levels. We found that although wild-type cells contain about approximately 200,000 molecules of Ess1, a level of fewer than 400 molecules per cell is sufficient for growth. In contrast, higher levels of Ess1 were required for growth in the presence of certain metabolic inhibitors, suggesting that Ess1 is important for tolerance to environmental challenge.
Links	PubMed Online version:10.1074/jbc.M412172200
Keywords	Cell Wall/metabolism; Mutation; Peptidylprolyl Isomerase/genetics; Peptidylprolyl Isomerase/metabolism; Saccharomyces cerevisiae/enzymology; Saccharomyces cerevisiae/growth & development
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
YEAST:ESS1	enables	GO:0003755: peptidyl-prolyl cis-trans isomerase activity	ECO:0000315: mutant phenotype evidence used in manual assertion		F		Seeded From UniProt	complete
YEAST:ESS1	enables	GO:0003755: peptidyl-prolyl cis-trans isomerase activity	ECO:0000314: direct assay evidence used in manual assertion		F		Seeded From UniProt	complete
YEAST:ESS1	involved_in	GO:0000413: protein peptidyl-prolyl isomerization	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
YEAST:ESS1	involved_in	GO:0000413: protein peptidyl-prolyl isomerization	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete

References

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