title: The high osmolarity glycerol response (HOG) MAP kinase pathway controls localization of a yeast golgi glycosyltransferase.
abstract: The yeast alpha-1,3-mannosyltransferase (Mnn1p) is localized to the Golgi by independent transmembrane and lumenal domain signals. The lumenal domain is localized to the Golgi complex when expressed as a soluble form (Mnn1-s) by exchange of its transmembrane domain for a cleavable signal sequence (Graham, T. R., and V. A. Krasnov. 1995. Mol. Biol. Cell. 6:809-824). Mutants that failed to retain the lumenal domain in the Golgi complex, called lumenal domain retention (ldr) mutants, were isolated by screening mutagenized yeast colonies for those that secreted Mnn1-s. Two genes were identified by this screen, HOG1, a gene encoding a mitogen-activated protein kinase (MAPK) that functions in the high osmolarity glycerol (HOG) pathway, and LDR1. We have found that basal signaling through the HOG pathway is required to localize Mnn1-s to the Golgi in standard osmotic conditions. Mutations in HOG1 and LDR1 also perturb localization of intact Mnn1p, resulting in its loss from early Golgi compartments and a concomitant increase of Mnn1p in later Golgi compartments.
authors.affiliation: Department of Molecular Biology, Vanderbilt University, Nashville, Tennessee 37235, USA.
authors.forename: T B
authors.initials: TB
authors.lastname: Reynolds
authors.forename: B D
authors.initials: BD
authors.lastname: Hopkins
authors.forename: M R
authors.initials: MR
authors.lastname: Lyons
authors.forename: T R
authors.initials: TR
authors.lastname: Graham
mesh_terms: D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry / Q000201:enzymology; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005816:Genetic Complementation Test; D016695:Glycosyltransferases / Q000378:metabolism*; D006056:Golgi Apparatus / Q000201:enzymology*; D020930:MAP Kinase Kinase Kinases; D008364:Mannosyltransferases; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases; D016296:Mutagenesis / Q000502:physiology; D009994:Osmolar Concentration; D010641:Phenotype; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011755:Pyrophosphatases / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction / Q000502:physiology; D015003:Yeasts / Q000201:enzymology / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D008562:Membrane Glycoproteins; D029701:Saccharomyces cerevisiae Proteins; D016695:Glycosyltransferases; C086604:MNN1 protein, S cerevisiae; D008364:Mannosyltransferases; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; D011755:Pyrophosphatases; C010357:guanosine-diphosphatase