The N-terminal coiled-coil domain of beta is essential for gamma association: a model for G-protein beta gamma subunit interaction.
AUTOR(ES)
Garritsen, A
RESUMO
We have identified the N terminus of the beta subunit as an essential domain for G-protein beta gamma assembly. A C-terminal fragment, beta 1-(130-340), fails to bind gamma unless coexpressed with the complementary N-terminal fragment, beta 1-(1-129). Deletion of the N-terminal 33 residues of beta 1, a region identified by computer algorithm to favor coiled-coil formation, abolishes gamma 2 association. On the basis of these findings, we propose a coiled-coil model of beta gamma interaction and refine this by computer-assisted molecular modeling. The model is tested by further mutagenesis: reversing the charge of residues in beta 1 that are hypothesized to be involved in interhelical salt bridges precludes gamma association. Insertions in the coiled-coil region, which disrupt the proposed hydrophobic interface, prevent gamma association. This structural basis for beta gamma dimerization provides a starting point for the design of beta and gamma mutants that can be used to map regions in beta gamma critical for interactions with the alpha subunit, receptors, and effectors.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=47211Documentos Relacionados
- Role of the Simian Virus 5 Fusion Protein N-Terminal Coiled-Coil Domain in Folding and Promotion of Membrane Fusion
- Regulation of c-Fes Tyrosine Kinase and Biological Activities by N-Terminal Coiled-Coil Oligomerization Domains
- Interaction between G-protein beta and gamma subunit types is selective.
- Coiled-coil domain-mediated FRQ–FRQ interaction is essential for its circadian clock function in Neurospora
- A Point Mutation in the N-Terminal Coiled-Coil Domain Releases c-Fes Tyrosine Kinase Activity and Survival Signaling in Myeloid Leukemia Cells