Glycosyl-phosphatidylinositol-phospholipase type D: a possible candidate for the generation of second messengers.
Membrane associated glycosyl-phosphatidylinositols have been shown to be the precursors of inositol phosphoglycan second messengers. Extraction of human liver membranes and purification by serial thin layer chromatography revealed three glycolipids which co-migrated with glycosyl-phosphatidylinositol from rat liver. These lipidic fractions were partially sensitive to treatment with nitrous acid and to hydrolysis by glycosyl-phosphatidylinositol-specific phospholipase D from bovine serum. In parallel, glycosyl-phosphatidylinositol isolated from rat liver was found to be a substrate for the enzyme generating a biologically active inositol phosphoglycan species (determined by measuring inhibition of protein kinase A activity and stimulation of cell proliferation within the chicken embryo cochleovestibular ganglion). This molecule was recognised by an anti-inositol phosphoglycan antibody. Hence, we propose that glycosyl-phosphatidylinositol-specific phospholipase D could be implicated in cellular signalling.
Jones
D R
DR
Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
Avila
M A
MA
Sanz
C
C
Varela-Nieto
I
I
D000818:Animals; D002417:Cattle; D002642:Chick Embryo; D002855:Chromatography, Thin Layer; D006801:Humans; D006868:Hydrolysis; D008099:Liver / Q000378:metabolism; D008297:Male; D010739:Phospholipase D / Q000378:metabolism*; D051381:Rats; D015290:Second Messenger Systems
D010739:Phospholipase D; C065017:glycoprotein phospholipase D