Rhodopsin is converted by light to an active photoproduct that triggers the transduction cascade. The active photoproduct must then be inactivated by some kind of chemical modification. The question addressed here is whether photoconversion of the inactive photoproduct to rhodopsin creates a modified form of rhodopsin that is unable to support transduction. This question was investigated in ult...

Treatment of outer segment membranes from Loligo forbesi with endoprotease-V8 from Staphylococcus aureus results in cleavage of the C-terminal extension of the squid rhodopsin, with accompanying reduction of the apparent molecular weight from 47,000 to 36,000 on sodium dodecyl sulfate/polyacrylamide gel electrophoresis. Negative-stain electron microscopy of the intact membranes shows that small...

Visual arrestin modulates the intracellular response of retinal rod cells to light by specifically binding to the phosphorylated light-activated form of the photoreceptor rhodopsin (P-Rh*). In order to characterize the molecular interaction between rhodopsin and arrestin, we have studied the ability of synthetic peptides from the proposed cytoplasmic loops of rhodopsin to inhibit arrestin bindi...

G protein-coupled receptor (GPCR) kinases (GRKs) selectively phosphorylate GPCRs in their activated states, priming them for arrestin binding and internalization. How GRKs recognize these receptors how turn on the kinase activity of is debated. Here we trapped a light rhodopsin (Rho*) complex with (GRK1) using novel crosslinker determined 4.0 Å cryo-EM structure this aid GRK1-binding Fab. GRK1-...

The influence of light environment on rhodopsin concentration per eye was determined in littermate pigmented and nonpigmented C57BL/6J-pallid gene mice reared under cyclic light or continuous dark environments. Attempts to exacerbate a congenital manganese deficiency in pallid strain mice included dietary deprivation and supplementation with manganese and exposure to intense light followed by t...

Rhodopsin, the red photosensitive pigment of rod vision, is composed of a specific cis isomer of retinene, neo-b (ll-c~s), joined as chromophore to a colorless protein, opsin. We have investigated the thermal denaturation of cattle rhodopsin and opsin in aqueous digitonin solution, and in isolated rod outer limbs. Both rhodopsin and opsin are more stable in rods than in solution. In solution as...

Contact sites in interaction between light-activated rhodopsin and transducin (T) have been investigated by using a chemically preactivated crosslinking reagent, N-succinimidyl 3-(2-pyridyldithio)propionate. The 3 propionyl-N-succinimidyl group in the reagent was attached by a disulfide exchange reaction to rhodopsin mutants containing single reactive cysteine groups in the cytoplasmic loops. C...

Rhodopsin, the red photosensitive pigment of rod vision, is composed of a specific cis isomer of retinene, neo-b (11-cis), joined as chromophore to a colorless protein, opsin. We have investigated the thermal denaturation of cattle rhodopsin and opsin in aqueous digitonin solution, and in isolated rod outer limbs. Both rhodopsin and opsin are more stable in rods than in solution. In solution as...

Purified rhodopsin has been prepared containing less than 1.1 mol of phosphate per mol of protein. The purified rhodopsin has been incorporated into phosphatidylcholine bilayers, and the molecular interactions within the bilayers were investigated by the use of spin-labeled phosphatidylcholines. Rhodopsin appears to inhibit segmental motions of the hydrocarbon chains, an effect similar to that ...