title: Polyphosphoinositol lipids in Chlamydomonas eugametos gametes.
abstract: In Chlamydomonas eugametos gametes, phosphatidylinositol 4-phosphate (PtdInsP) and phosphatidylinositol 4,5-bisphosphate (PtdInsP2) comprised 0.4 and 0.3% of the whole-cell phospholipids. They were concentrated in the plasma membrane around the cell body and were present in low concentrations in the flagellar membrane. When gametes were fed (32)PO 4 (-) , the label was rapidly incorporated into PtdInsP and PtdInsP2 and only slowly incorporated into structural lipids such as phosphatidylethanolamine and phosphatidylglycerol. Similarly, when a pulse of (32)PO 4 (-) was chased with PO 4 (-) , the label was rapidly lost from the polyphosphoinositol lipids but not from the structural lipids. The major fatty acids in the polyphosphoinositides were C-22 carbon polyenoic acids (70%). The significance of these results in relationship to intracellular signalling via inositol phosphates and Ca(2+) is discussed.
authors.affiliation: Department of Molecular Cell Biology, University of Amsterdam, Kruislaan 318, NL-1098, SM Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Brederoo
authors.forename: P
authors.initials: P
authors.lastname: de Wildt
authors.forename: C
authors.initials: C
authors.lastname: Popp-Snijders
authors.forename: R F
authors.initials: RF
authors.lastname: Irvine
authors.forename: A
authors.initials: A
authors.lastname: Musgrave
authors.forename: H
authors.initials: H
authors.lastname: van den Ende