N-terminal binding domain of Galpha subunits: involvement of amino acids 11-14 of Galphao in membrane attachment.
N-terminal binding domain of Galpha subunits: involvement of amino acids 11-14 of Galphao in membrane attachment.
复制标题
Galpha 亚基的 N 端结合域：Galphao 的氨基酸 11-14 参与膜附着。
DOI：
10.1042/bj3230239
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Denker,BM
中科院分区：
文献类型：
--
作者：
Busconi,L;Boutin,PM;Denker,BM
Heterotrimeric guanine nucleotide binding proteins (G-proteins) transmit signals from membrane receptors to a variety of intracellular effectors. G-proteins reversibly associate with components of the signal transduction system, yet remain membrane attached throughout the cycle of activation. The Gα subunits remain attached to the plasma membrane through a combination of factors that are only partially defined. We now demonstrate that amino acids within the N-terminal domain of Gα subunits are involved in membrane binding. We usedin vitrotranslation, a technique widely utilized to characterize functional aspects of G-proteins, and interactions with donor-acceptor membranes to demonstrate that amino acids 11-14 of Gαocontribute to membrane binding. The membrane binding of Gαolacking amino acids 11-14 (D[11-14]) was significantly reduced at all membrane concentrations in comparison with wild-type Gαo. Several other N-terminal mutants of Gαowere characterized as controls, and these results indicate that differences in myristoylation, palmitoylation and βγ interactions do not account for the reduced membrane binding of D[11-14]. Furthermore, when membrane attachment of Gαoand mutants was characterized in transiently transfected35S-labelled and [3H]myristate-labelled COS cells, amino acids 11-14 contributed to membrane binding. These studies reveal that membrane binding of Gα subunits occurs by a combination of factors that include lipids and amino acid sequences. These regions may provide novel sites for interaction with membrane components and allow additional modulation of signal transduction.
