Strahl-Bolsinger, Sabine and Scheinost, Alexandra (1999) Transmembrane topology of Pmt1p, a member of an evolutionarily conserved family of protein O-mannosyltransferases. JOURNAL OF BIOLOGICAL CHEMISTRY, 274 (13). pp. 9068-9075. ISSN 0021-9258,
Full text not available from this repository. (Request a copy)Abstract
The identification of the evolutionarily conserved family of dolichyl-phosphate-D-mannose:protein O-mannosyltransferases (Pmts) revealed that protein O-mannosylation plays an essential role in a number of physiologically important processes, Strikingly, all members of the Pmt protein family share almost identical hydropathy profiles; a central hydrophilic domain is flanked by amino- and carboxyl-terminal sequences containing several putative transmembrane helices, This pattern is of particular interest because it diverges from structural models of all glycosyltransferases characterized so far. Here, we examine the transmembrane topology of Pmt1p, an integral membrane protein of the endoplasmic reticulum, from Saccharomyces cerevisiae. Structural predictions were directly tested by site-directed mutagenesis of endogenous N-glycosylation sites, by fusing a topology-sensitive monitor protein domain to carboxyl-terminal truncated versions of the Pmt1 protein and, in addition, by N-glycosylation scanning. Based on our results we propose a seven-transmembrane helical model for the yeast Pmt1p mannosyltransferase. The Pmt1p amino terminus faces the cytoplasm, whereas the carboxyl terminus faces the lumen of the endoplasmic reticulum, A large hydrophilic segment that is oriented toward the lumen of the endoplasmic reticulum is flanked by five amino-terminal and two carboxyl-terminal membrane spanning domains. We could demonstrate that this central loop is essential for the function of Pmt1p.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | LIPID-LINKED OLIGOSACCHARIDE; PHOSPHATE N-ACETYLGLUCOSAMINE-1-PHOSPHATE TRANSFERASE; INNER MEMBRANE-PROTEINS; SACCHAROMYCES-CEREVISIAE; ENDOPLASMIC-RETICULUM; GENE FAMILY; GLCNAC-1-P TRANSFERASE; CANDIDA-ALBICANS; N-GLYCOSYLATION; PIG-B; |
| Subjects: | 500 Science > 580 Botanical sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Pflanzenwissenschaften > Lehrstuhl für Zellbiologie und Pflanzenphysiologie (Prof. Dr. Klaus Grasser) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 08 Nov 2022 15:11 |
| Last Modified: | 08 Nov 2022 15:11 |
| URI: | https://pred.uni-regensburg.de/id/eprint/48423 |
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