title: Cdc4 is involved in the transcriptional control of OCH1, a gene encoding alpha-1,6-mannosyltransferase in Saccharomyces cerevisiae.
abstract: The Saccharomyces cerevisiae OCH1 gene encodes an alpha-1,6-mannosyltransferase that initiates the polymannose outer chain elongation of N-linked glycans. Transcription of OCH1 is regulated by two transcription factors, Swi4 and Skn7. To learn more about the signals that feed into the Swi4 regulation, we isolated a mutant, bon1-1 (bypass of Skn7), that activates OCH1-HIS3 and OCH1-lacZ reporters in a strain deleted for SKN7. bon1-1 is an allele of CDC4 (cdc4(bon)) and leads to the additional phenotypes of temperature sensitivity and abnormal cell morphology. The cdc4(bon) mutant is partially suppressed by CLB5 overexpression and accumulates Sic1 protein, indicating that OCH1 transcription is controlled by the ubiquitin-dependent degradation pathway through the Skp1-Cdc53-F box(Cdc4) protein complex. We suggest that transcriptional control of OCH1 by cdc4(bon) is through Swi4, because cdc4(bon) cannot activate the OCH1-lacZ reporter in a strain deleted for SWI4. Interestingly, cdc4(bon) and Delta swi4 show a synthetic growth defect when combined.
authors.affiliation: Institute of Molecular and Cell Biology, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Cui
authors.forename: Joe
authors.initials: J
authors.lastname: Horecka
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Jigami
mesh_terms: D000483:Alleles; D018797:Cell Cycle Proteins / Q000235:genetics*; D019926:Cyclin B / Q000502:physiology; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D004268:DNA-Binding Proteins / Q000235:genetics; D044783:F-Box Proteins; D005656:Fungal Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D008364:Mannosyltransferases / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000235:genetics*; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D044767:Ubiquitin-Protein Ligases
chemical_list: C080443:CDC4 protein, S cerevisiae; C076558:CLB5 protein, S cerevisiae; D018797:Cell Cycle Proteins; D019926:Cyclin B; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D004268:DNA-Binding Proteins; D044783:F-Box Proteins; D005656:Fungal Proteins; D008562:Membrane Glycoproteins; C075636:OCH1 protein, S cerevisiae; C086926:SIC1 protein, S cerevisiae; C083962:SKN7 protein, S cerevisiae; C062214:SWI4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases; D008364:Mannosyltransferases