Carboxyl methylation and farnesylation of transducin gamma-subunit synergistically enhance its coupling with metarhodopsin II.
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منابع مشابه
Farnesylation of the Transducin G Protein Gamma Subunit Is a Prerequisite for Its Ciliary Targeting in Rod Photoreceptors
Primary cilia are microtubule-based organelles, which protrude from the plasma membrane and receive a wide range of extracellular signals. Various cilia use G protein-coupled receptors (GPCRs) for the detection of these signals. For instance, vertebrate rod photoreceptors use their cilia (also called outer segments) as antennae detecting photons by GPCR rhodopsin. Rhodopsin recognizes incoming ...
متن کاملFarnesylation of Retinal Transducin Underlies Its Translocation during Light Adaptation
G proteins are posttranslationally modified by isoprenylation: either farnesylation or geranylgeranylation. The gamma subunit of retinal transducin (Talpha/Tbetagamma) is selectively farnesylated, and the farnesylation is required for light signaling mediated by transducin in rod cells. However, whether and how this selective isoprenylation regulates cellular functions remain poorly understood....
متن کاملInteractions of metarhodopsin II. Arrestin peptides compete with arrestin and transducin.
Arrestin blocks the interaction of rhodopsin with the G protein transducin (G(t)). To characterize the sites of arrestin that interact with rhodopsin, we have utilized a spectrophotometric peptide competition assay. It is based on the stabilization of the active intermediates metarhodopsin II (MII) and phosphorylated MII by G(t) and arrestin, respectively (extra MII monitor). The protocol invol...
متن کاملStructure and function in rhodopsin: covalent crosslinking of the rhodopsin (metarhodopsin II)-transducin complex--the rhodopsin cytoplasmic face links to the transducin alpha subunit.
We prepared rhodopsin mutants that contained a single reactive cysteine residue per rhodopsin molecule at position 65, 140, 240, or 316 on the cytoplasmic face. A carbene-generating photoactivatable group was linked by a disulfide bond to the cysteine sulfhydryl group of each of the rhodopsin mutants. The resulting derivative was then light-activated at lambda > 495 nm to form the metarhodopsin...
متن کاملCarboxyl methylation and COOH-terminal processing of the brain G-protein gamma-subunit.
The enzymatic methylation of the guanine nucleotide-binding proteins (G-proteins) gamma-subunit was investigated in brain membranes. Brain membranes were methylated in vitro using [3H-methyl]S-adenosylmethionine, and the G-protein beta gamma-complex was purified using an anti-beta antibody to assay for the protein during purification. The isolated G-protein beta gamma-complex was found to be ca...
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ژورنال
عنوان ژورنال: The EMBO Journal
سال: 1991
ISSN: 0261-4189
DOI: 10.1002/j.1460-2075.1991.tb04934.x