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Mol Biol Cell

Title:		"The yeast Ca(2+)-ATPase homologue, PMR1, is required for normal Golgi function and localizes in a novel Golgi-like distribution"
Author(s):		Antebi A; Fink GR;
Address:		"Whitehead Institute of Biomedical Research, Cambridge, Massachusetts"
Journal Title:		Mol Biol Cell
Year:		1992
Volume:		3
Issue:		6
Page Number:		633 - 654
DOI:		10.1091/mbc.3.6.633
ISSN/ISBN:		1059-1524 (Print) 1059-1524 (Linking)
Abstract:		"PMR1, a Ca(2+)-adenosine triphosphatase (ATPase) homologue in the yeast Saccharomyces cerevisiae localizes to a novel Golgi-like organelle. Consistent with a Golgi localization, the bulk of PMR1 comigrates with Golgi markers in subcellular fractionation experiments, and staining of PMR1 by indirect immunofluorescence reveals a punctate pattern resembling Golgi staining in yeast. However, PMR1 shows only partial colocalization with known Golgi markers, KEX2 and SEC7, in double-label immunofluorescence experiments. The effect of PMR1 on Golgi function is indicated by pleiotropic defects in various Golgi processes in pmr1 mutants, including impaired proteolytic processing of pro-alpha factor and incomplete outer chain glycosylation of invertase. Consistent with the proposed role of PMR1 as a Ca2+ pump, these defects are reversed by the addition of millimolar levels of extracellular Ca2+, suggesting that Ca2+ disposition is essential to normal Golgi function. Absence of PMR1 function partially suppresses the temperature-sensitive growth defects of several sec mutants, and overexpression of PMR1 restricts the growth of others. Some of these interactions are modulated by changes in external Ca2+ concentrations. These results imply a global role for Ca2+ in the proper function of components governing transit and processing through the secretory pathway"
Keywords:		"Amino Acid Sequence Base Sequence Biological Transport/physiology Calcium-Transporting ATPases/analysis/*physiology Carboxypeptidases/analysis Cathepsin A Epitopes Fungal Proteins/analysis/*metabolism Genes, Fungal/physiology Glycosylation Golgi Apparatus;"
Notes:		"MedlineAntebi, A Fink, G R eng GM-35010/GM/NIGMS NIH HHS/ GM-40266/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, P.H.S. 1992/06/01 Mol Biol Cell. 1992 Jun; 3(6):633-54. doi: 10.1091/mbc.3.6.633"