The α‐subunits of G‐proteins G12 and G13 are palmitoylated, but not amidically myristoylated

FEBS Letters

Spicher, Karsten²  Veit, Michael¹  Schultz, Günter²  Ponimaskin, Ewgeni¹  Schmidt, Michael F.G.¹  Harteneck, Christian²  Nürnberg, Bernd² 

[1] Institut für Immunologie und Molekularbiologie, Freie Universität Berlin, Fachbereich Veterinärmedizin, Königin-Luise-Str. 49, 14195 Berlin, Germany;Institut für Pharmakologie, Universitätsklinikum Rudolf Virchow, Freie Universität Berlin, Thielallee 69-73, 14195 Berlin, Germany

关键词: Palmitoylation;    G-protein;    G12;    G13;    Acylation;    Baculovirus expression;   

DOI  :  10.1016/0014-5793(94)80406-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The α-subunits of the G-proteins G₁₂ and G₁₃, 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 [³H]palmitic acid showed that palmitate represents the predominant fatty acid linked to Gα₁₂ and Gα₁₃. Separation of cells into cytosolic and membranous fractions revealed that palmitoylated α-subunits of G₁₂ were exclusively membrane-bound, whereas [³⁵S]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.

【 授权许可】

Unknown