Diacylglycerols and phosphatidates: which molecular species are intracellular messengers?
In eukaryotes, many receptor agonists use phospholipase-generated lipids as intracellular messengers. Receptor occupation stimulates the production of polyunsaturated 1,2-diacylglycerols by phosphatidylinositol-4,5-bisphosphate specific phospholipases C and/or of mono-unsaturated and saturated phosphatidates by phospholipase-D-catalysed phosphatidylcholine breakdown. The primary phospholipase products are rapidly metabolized: polyunsaturated 1,2-diacylglycerols are converted to polyunsaturated phosphatidates by diacylglycerol kinase; mono-unsaturated and saturated phosphatidates are dephosphorylated to give mono-unsaturated and saturated 1,2-diacylglycerols by phosphatidate phosphohydrolase. The phospholipase-generated polyunsaturated 1,2-diacylglycerols and mono-unsaturated and saturated phosphatidates appear to be intracellular messengers, whereas their immediate metabolites probably do not have signalling functions.
Hodgkin
M N
MN
Institute for Cancer Studies, University of Birmingham Edgbaston, UK.
Pettitt
T R
TR
Martin
A
A
Michell
R H
RH
Pemberton
A J
AJ
Wakelam
M J
MJ
D000818:Animals; D004075:Diglycerides / Q000502:physiology*; D006801:Humans; D008958:Models, Molecular; D010712:Phosphatidic Acids / Q000502:physiology*; D015290:Second Messenger Systems / Q000502:physiology*
D004075:Diglycerides; D010712:Phosphatidic Acids