Disease relevance of opn1sw-A

• Opsin activation as a cause of congenital night blindness [1].
• In combination with the previously reported X. laevis opsin and arrestin promoters, these sequences will facilitate the development and analysis of X. laevis models of inherited retinal degeneration [2].

High impact information on opn1sw-A

• Evidence that microtubules do not mediate opsin vesicle transport in photoreceptors [3].
• Polyacrylamide gel electrophoresis revealed that TM had little effect on the incorporation of [3H]leucine into the proteins of whole retinas and that labeling of proteins (especially opsin) in isolated rod outer segment (ROS) membranes was negligible [4].
• These results demonstrate that TM can block retinal protein glycosylation and normal disc membrane assembly under conditions where synthesis and intracellular transport of rod cell proteins (e.g., opsin) are not inhibited [4].
• Melanopsin: An opsin in melanophores, brain, and eye [5].
• Analysis of NaDodSO4/PAGE fluorograms of solubilized retinas and rod outer segment (ROS) membranes indicated a relatively selective effect of Cas on opsin (the rod visual pigment apoglycoprotein) [6].

Biological context of opn1sw-A

• Thus, opsin bearing abnormally large oligosaccharides can be accommodated in the process of disc morphogenesis [6].
• By comparing the response sensitivity before stage 53 to the sensitivity at/after stage 53 measured from rods that had been subjected to various known bleaches, we estimated that 22-28% of rod opsin in stage 50-52 tadpoles (i.e., before stage 53) was devoid of chromophore despite overnight dark-adaptation [7].
• Opsin gene expression, synthesis, and photoreceptor outer segment morphology were evaluated during retinal development in Xenopus laevis [8].
• Melanopsin (Opn4) is a novel opsin involved in entrainment of circadian rhythms in mammals [9].
• The long-wavelength sensitive (red) opsin genes encode proteins which play a central role in daytime and color vision in vertebrates [10].

Anatomical context of opn1sw-A

• The disposition of opsin immunoreactivity in the cell membrane was highly asymmetric [11].
• During development, IRBP and opsin mRNA expression correlates with photoreceptor differentiation [12].
• These results demonstrate that intracellular vesicular membranes transport newly synthesized opsin from the Golgi to the base of the connecting cilium of X. laevis retinas [13].
• Vesicular transport of newly synthesized opsin from the Golgi apparatus toward the rod outer segment. Ultrastructural immunocytochemical and autoradiographic evidence in Xenopus retinas [13].
• An opsin-encoding cDNA was cloned from the marine alga Acetabularia acetabulum [14].

Associations of opn1sw-A with chemical compounds

• When assays were performed with lambda > 420 nm illumination, VCOP exhibited rapid regeneration and high affinity for the photoregenerated 11-cis-retinal [15].
• Tunicamycin (TM), a selective inhibitor of dolichylphosphate-dependent oligosaccharide biosynthesis, effectively blocks glycosylation, but not synthesis, of opsin, the rod visual pigment apoglycoprotein [16].
• The formation of this material is apparently a consequence of a deficiency in newly synthesized, asparagine-linked membrane glycoconjugates (e.g., the oligosaccharide chains of opsin) at the site of disc assembly [17].
• Like all visual pigments, this class has an 11-cis-retinal chromophore attached through a Schiff base linkage to a lysine residue of opsin apoprotein [18].
• FTIR spectroscopy of violet cone opsin indicates conclusively that the chromophore is protonated [19].

Other interactions of opn1sw-A

• The injected caps expressed a general neural marker NCAM and the forebrain marker opsin [20].
• Sections of X. laevis eyes were analyzed by immunocytochemistry and confocal microscopy, in combination with antibodies against the Mel1a melatonin receptor, a rod photoreceptor-specific protein, opsin, and two amacrine cell-specific markers, tyrosine hydroxylase (TOH; dopaminergic cells) and glutamic acid decarboxylase (GAD; GABA-ergic cells) [21].

Analytical, diagnostic and therapeutic context of opn1sw-A

• Sequence analysis shows that within the coding region Xenopus opsin shares a high degree of identity with other rod opsin genes, except at the C-terminal where it more closely resembles the mammalian color opsins [22].
• Cyclic GMP-activated currents were measured in excised, inside-out membrane patches before and after treatment with either all-trans retinal (ATR) or all-trans C22 aldehyde, which is too long to fit into the chromophore binding pocket of opsin and therefore cannot activate the visual transduction cascade [23].

References