A novel intracellular membrane-bound calcium-independent phospholipase A(2).
We have cloned human cDNA encoding a novel protein of 782 amino acids that contains the lipase consensus sequence Gly-Xaa-Ser-Xaa-Gly and several stretches surrounding the motif, which are homologous to those of the catalytic domain of cytosolic calcium-independent phospholipase A(2) (iPLA(2)). When expressed in COS-7 cells, the protein predominantly exists in the membrane fraction and exhibits a phospholipase A(2) activity in a calcium-independent manner. The transcript of the membrane-bound iPLA(2) gene is ubiquitously observed as a single band of approximately 3.3 kb on Northern blot, with the most abundant expression in the skeletal muscle and heart. By a search of the database, we have also identified its putative C. elegans homologue, which shows 47% identity with that of human in the iPLA(2) catalytic region. Thus the novel type of iPLA(2) is evolutionarily well conserved, suggestive of its biological significance.
Tanaka
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H
Department of Molecular and Structural Biology, Kyushu University Graduate School of Medical Science, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Takeya
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R
Sumimoto
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D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001483:Base Sequence; D019556:COS Cells; D017173:Caenorhabditis elegans / Q000201:enzymology / Q000235:genetics; D002122:Calcium Chloride / Q000494:pharmacology; D020134:Catalytic Domain; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D003001:Cloning, Molecular; D020224:Expressed Sequence Tags; D054522:Group VI Phospholipases A2; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010741:Phospholipases A / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D015801:Helminth Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D016718:Arachidonic Acid; D010741:Phospholipases A; D054522:Group VI Phospholipases A2; C516475:PLA2G6 protein, human; D002122:Calcium Chloride