title: Proteolytic processing of the Saccharomyces cerevisiae cell wall protein Scw4 regulates its activity and influences its covalent binding to glucan.
abstract: Yeast cell wall contains a number of proteins that are either non-covalently (Scw-proteins), or covalently (Ccw-proteins) bound to β-1,3-glucan, the latter either through GPI-anchors and β-1,6-glucan, or by alkali labile ester linkages between γ-carboxyl groups of glutamic acid and hydroxyl groups of glucoses (Pir-proteins). It was shown that a part of Scw4, previously identified among the non-covalently bound cell wall proteins, was covalently attached to wall polysaccharides by a so far unknown alkali sensitive linkage. Thus Scw4 could be released from cell walls by treatments with hot SDS, mild alkali, or β-1,3-glucanases, respectively. It was further shown that non-covalently bound Scw4 (SDS released) underwent the Kex2 proteolytic processing. In this paper it was demonstrated that Scw4 was also processed by yapsins at a position 9 amino acids downstream of the Kex2 cleavage site. Scw4 cleaved at the yapsin site had a markedly lower potential for covalent attachment to glucan. The overproduction of the fully processed form of Scw4 lead to high mortality, particularly in the stationary phase of growth, and to markedly increased cell size. On the other hand, the overproduction of Scw4 processed only by Kex2 or not processed at all had no apparent change in mortality indicating that only the smallest, completely mature form of Scw4 had the activity leading to observed phenotype changes.
authors.affiliation: Laboratory of Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia.
authors.forename: Antonija
authors.initials: A
authors.lastname: Grbavac
authors.affiliation: Laboratory of Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia.
authors.forename: Iva
authors.initials: I
authors.lastname: Čanak
authors.affiliation: Laboratory of Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia.
authors.forename: Igor
authors.initials: I
authors.lastname: Stuparević
authors.affiliation: Laboratory of Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia.
authors.forename: Renata
authors.initials: R
authors.lastname: Teparić
authors.affiliation: Laboratory of Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia. Electronic address: vmrsa@pbf.hr.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Mrša
mesh_terms: D000595:Amino Acid Sequence; D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism; D048429:Cell Size; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism*; D015870:Gene Expression; D005959:Glucosidases / Q000235:genetics / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D050296:Microbial Viability; D010641:Phenotype; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D043484:Proprotein Convertases / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D059748:Proteolysis; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D047071:beta-Glucans / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D047071:beta-Glucans; C064197:beta-1,6-glucan; C033363:beta-1,3-glucan; D005959:Glucosidases; C000623104:Scw4 protein, S cerevisiae; D043484:Proprotein Convertases; C058751:KEX2 protein, S cerevisiae; D016282:Aspartic Acid Endopeptidases; C499266:YPS1 protein, S cerevisiae
keywords: Cell wall proteins; Kex2; Proteolytic processing; Scw4; Yapsins; Yeast cell wall