The Saccharomyces cerevisiae SAC1 gene modulates yeast actin function and alleviates the essential requirement for phosphatidylinositol transfer protein (sec14p) activity in Golgi secretory function. The SAC1 gene product (Sac1p) is an integral membrane lipid phosphatase of the endoplasmic reticulum (ER) and the Golgi complex and contains a Sac phosphatase domain (1-2). Sac1p functions in a wide range of cellular processes including inositol metabolism, actin cytoskeletal organization, endoplasmic reticulum ATP transport, phosphatidylinositol-phospha-tidylcholine transfer protein function and multiple-drug sensitivity (3). Sac1p is an important regulator of microsomal ATP transport, providing a link between inositol phospholipid signaling and ATP-dependent processes in the yeast ER (4). Defects in Sac1p relieves the requirement for Sec14p by altering phospholipid metabolism to expand the pool of diacylglycerol in the Golgi (5). Sac1p dysfunction exerts its pleiotropic effects on yeast Golgi function, the organization of the actin cytoskeleton, and the cellular requirement for inositol, through altered metabolism of inositol glycerophospholipids (6). These effects suggest the secretory and cytoskeletal activities are coordinated to achieve proper spatial regulation of secretion in S. cerevisiae (7).
Function:
Phosphoinositide phosphatase that hydrolyzes PtdIns(3)P and PtdIns(4)P. Has low activity towards PtdIns(3,5)P2.
Subcellular Location:
Endoplasmic reticulum membrane.
Tissue Specificity:
Detected in heart, brain, lung, liver, kidney, pancreas and testis.
Similarity:
Contains 1 SAC domain.
SWISS:
Q9NTJ5
Gene ID:
22908
Database links:
Entrez Gene: 530577 Cow
Entrez Gene: 484795 Dog
Entrez Gene: 101787561 Guinea pig
Entrez Gene: 100065601 Horse
Entrez Gene: 22908 Human
Entrez Gene: 83493 Mouse
Entrez Gene: 116482 Rat
Entrez Gene: 791142 Zebrafish
Omim: 606569 Human
SwissProt: A6QL88 Cow
SwissProt: Q9NTJ5 Human
SwissProt: Q9EP69 Mouse
SwissProt: Q9ES21 Rat
SwissProt: A1L244 Zebrafish
Unigene: 156509 Human
Unigene: 273671 Mouse
Unigene: 161978 Rat
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