期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1999
卷号：96
期号：2
页码：412-417
DOI：10.1073/pnas.96.2.412
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Heterotrimeric signal-transducing G proteins are organized at the inner surface of the plasma membrane, where they are positioned to interact with membrane-spanning receptors and appropriate effectors. G proteins are activated when they bind GTP and inactivated when they hydrolyze the nucleotide to GDP. However, the topological fate of activated G protein subunits is disputed. One model declares that depalmitoylation of , which accompanies activation by a receptor, promotes release of the protein into the cytoplasm. Our data suggest that activation of G protein subunits causes them to concentrate in subdomains of the plasma membrane but not to be released from the membrane. Furthermore, subunits remained bound to the membrane when they were activated with guanosine 5'-(3-O-thio)triphosphate and depalmitoylated with an acyl protein thioesterase. Limitation of subunits to the plasma membrane obviously restricts their mobility and may contribute to the efficiency and specificity of signaling.
