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The α‐subunits of G‐proteins G 12 and G 13 are palmitoylated, but not amidically myristoylated
Author(s) -
Veit Michael,
Nürnberg Bernd,
Spicher Karsten,
Harteneck Christian,
Ponimaskin Ewgeni,
Schultz Günter,
Schmidt Michael F.G.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80406-0
Subject(s) - palmitoylation , myristoylation , palmitic acid , myristic acid , biochemistry , chemistry , hydroxylamine , fatty acid , iodoacetamide , cytosol , acylation , g alpha subunit , thioester , cycloheximide , acyltransferases , lipid anchored protein , protein subunit , protein biosynthesis , cysteine , biosynthesis , membrane , enzyme , gene , apoptosis , autophagy , catalysis
The α‐subunits of the G‐proteins G 12 and G 13 , were expressed with a baculovirus system in insect cells and analysed for acylation. Both proteins incorporated tritiated palmitic and to a lesser extent also tritiated myristic acid. Radiolabel from both fatty acids was sensitive to treatment with neutral hydroxylamine. This result supports a thioester‐type fatty acid bond and argues against amidical N ‐myristoylation. Fatty acid analysis after labeling with [ 3 H]palmitic acid showed that palmitate represents the predominant fatty acid linked to Gα 12 and Gα 13 . Separation of cells into cytosolic and membranous fractions revealed that palmitoylated α‐subunits of G 12 were exclusively membrane‐bound, whereas [ 35 S]methionine‐labeled proteins were detected in soluble and particulate fractions. Inhibition of protein synthesis with cycloheximide did not block palmitoylation of the α‐subunits. which indicates that palmitoylation occurs independently of protein synthesis.