title: Identification of yeast Rho1p GTPase as a regulatory subunit of 1,3-beta-glucan synthase.
abstract: 1,3-beta-D-glucan synthase [also known as beta(1-->3) glucan synthase] is a multi-enzyme complex that catalyzes the synthesis of 1,3-beta-linked glucan, a major structural component of the yeast cell wall. Temperature-sensitive mutants in the essential Rho-type guanosine triphosphatase (GTPase), Rho1p, displayed thermolabile glucan synthase activity, which was restored by the addition of recombinant Rho1p. Glucan synthase from mutants expressing constitutively active Rho1p did not require exogenous guanosine triphosphate for activity. Rho1p copurified with beta(1-->3)glucan synthase and associated with the Fks1p subunit of this complex in vivo. Both proteins were localized predominantly at sites of cell wall remodeling. Therefore, it appears that Rho1p is a regulatory subunit of beta(1-->3)glucan synthase.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Qadota
authors.forename: C P
authors.initials: CP
authors.lastname: Python
authors.forename: S B
authors.initials: SB
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Arisawa
authors.forename: Y
authors.initials: Y
authors.lastname: Anraku
authors.forename: Y
authors.initials: Y
authors.lastname: Zheng
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: D E
authors.initials: DE
authors.lastname: Levin
authors.forename: Y
authors.initials: Y
authors.lastname: Ohya
mesh_terms: D020558:GTP Phosphohydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005964:Glucosyltransferases / Q000737:chemistry / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism; D008565:Membrane Proteins; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D013696:Temperature; D020741:rho GTP-Binding Proteins
chemical_list: D008565:Membrane Proteins; D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D005964:Glucosyltransferases; C020570:1,3-beta-glucan synthase; D011493:Protein Kinase C; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; C051302:RHO1 protein, S cerevisiae; D020741:rho GTP-Binding Proteins; C511156:rho1 protein, S pombe