Schiff-base deprotonation is mandatory for light-dependent rhodopsin phosphorylation
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چکیده
منابع مشابه
Electric-field-induced Schiff-base deprotonation in D85N mutant bacteriorhodopsin.
The application of an external electric field to dry films of Asp-85-->Asn mutant bacteriorhodopsin causes deprotonation of the Schiff base, resulting in a shift of the optical absorption maximum from 600 nm to 400 nm. This is in marked contrast to the case of wild-type bacteriorhodopsin films, in which electric fields produce a red-shifted product whose optical properties are similar to those ...
متن کاملA Schiff base connectivity switch in sensory rhodopsin signaling.
Sensory rhodopsin I (SRI) in Halobacterium salinarum acts as a receptor for single-quantum attractant and two-quantum repellent phototaxis, transmitting light stimuli via its bound transducer HtrI. Signal-inverting mutations in the SRI-HtrI complex reverse the single-quantum response from attractant to repellent. Fast intramolecular charge movements reported here reveal that the unphotolyzed SR...
متن کاملHis166 Is the Schiff Base Proton Acceptor in Attractant Phototaxis Receptor Sensory Rhodopsin I
Photoactivation of attractant phototaxis receptor sensory rhodopsin I (SRI) in Halobacterium salinarum entails transfer of a proton from the retinylidene chromophore's Schiff base (SB) to an unidentified acceptor residue on the cytoplasmic half-channel, in sharp contrast to other microbial rhodopsins, including the closely related repellent phototaxis receptor SRII and the outward proton pump b...
متن کاملThe pKa of the protonated Schiff bases of gecko cone and octopus visual pigments.
A visual pigment is composed of retinal bound to its apoprotein by a protonated Schiff base linkage. Light isomerizes the chromophore and eventually causes the deprotonation of this Schiff base linkage at the meta II stage of the bleaching cycle. The meta II intermediate of the visual pigment is the active form of the pigment that binds to and activates the G protein transducin, starting the vi...
متن کاملLight-stimulated phosphorylation of rhodopsin in the retina: the presence of a protein kinase that is specific for photobleached rhodopsin.
A protein kinase has been extracted from bovine rod outer segments by a mild procedure. The enzyme acts specifically on photobleached, not unbleached, rhodopsin and will not catalyze the phosphorylation of histones, phosvitin, or casein. We propose the name "opsin kinase" for the enzyme, which is not affected by cyclic nucleotides but which is inhibited by theophylline. Preparations of purified...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1989
ISSN: 0264-6021,1470-8728
DOI: 10.1042/bj2640489