Abstract
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 α subunits is disputed. One model declares that depalmitoylation of α, which accompanies activation by a receptor, promotes release of the protein into the cytoplasm. Our data suggest that activation of G protein α subunits causes them to concentrate in subdomains of the plasma membrane but not to be released from the membrane. Furthermore, α 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 α subunits to the plasma membrane obviously restricts their mobility and may contribute to the efficiency and specificity of signaling.
Original language | English (US) |
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Pages (from-to) | 412-417 |
Number of pages | 6 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 96 |
Issue number | 2 |
DOIs | |
State | Published - Jan 19 1999 |
Keywords
- Immunofluorescence
- Localization
- Signal transduction
- Thioesterase
ASJC Scopus subject areas
- General