opsin


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Related to opsin: rhodopsin, opsonin, KIPRIS

op·sin

(op'sin),
The protein portion of the rhodopsin molecule; at least three separate opsins are located in cone cells.

opsin

(ŏp′sĭn)
n.
Any of various light-sensitive proteins, especially one that is a constituent of a rhodopsin or other visual pigment found in the retina of the vertebrate eye.

op·sin

(op'sin)
The protein portion of the rhodopsin molecule; at least three separate opsins are located in cone cells.

opsin

a protein that occurs in rods and cones of the RETINA of the eye, which combines with retinal 1 or retinal2 to form visual pigments.

rhodopsin 

Visual pigment contained in the outer segments of the rod cells of the retina and involved in scotopic vision. When light stimulates the retina, the chromophore of the pigment molecule '11-cis' retinal (which is vitamin A aldehyde) isomerizes to 'all-trans' retinal. This leads to other chemical transformations which carry on even in the absence of light. The first stage is prelumirhodopsin, then lumirhodopsin and finally metarhodopsin (of which there are two types). This last transformation may lead to the breakdown of the molecule into retinal and opsin. The molecule is regenerated by recombining retinal and opsin with some enzymes. The absorption spectrum of rhodopsin has a maximum around 498 nm. The isomerization from '11-cis' to 'all-trans' also gives rise to the process of transduction in which the membrane potential covering the pigment molecules in the outer segment changes towards a hyperpolarization of the cell. This is the first step in the nervous response to a light stimulation of the retina. Syn. visual purple (not used any more); erythropsin. See dark adaptation; bleaching; receptor potential; absorption spectrum; transduction.
References in periodicals archive ?
Opsin gene structure suggests a closer relationship between Limulus LWS opsins and peropsins, a Group 4 opsin, than is expected based on the phylogeny shown in Figure 2.
"We've found the role of opsin 3 in human melanocytes and figured out the molecular steps that allow opsin 3 to achieve this function," Oancea said.
To test their theory, scientists injected the silver spiny fish's genes into bacteria and generated rod opsins that they then tested in the lab for sensitivity to light.
Opsins and clusters of sensory G-protein-coupled receptors in the sea urchin genome.
isolated and purified L/M opsin GFP cones from hPSC-derived W17-20 retinal organoids by FACS for transplantation, yielding approximately 7% L/M cones [13].
Rollag, "A novel human opsin in the inner retina," Journal of Neuroscience, vol.
Esther Ullrich-Luter's opsin search was all about sea urchins when she worked in Maria Ina Arnone's lab at the Anton Dohrn Zoological Station in Naples, Italy.
Opsin genes, categorized according to the peak of light spectra that the opsin protein absorbs when it interacts with the chromophore, are responsible for color vision by absorbing short-wavelengths SWS1, SWS2A, SWS2B, medium-wavelength RH2A and RH2B, and long-wavelength LWS (Terakita, 2005; Carleton, 2009).
Deisseroths microbial opsin research came after he had concluded a decidedly different pursuit: a residency in clinical psychiatry.
For example, Opsin 5 in the paraventricular organ of quail appears to be a deep brain photoreceptive molecule that regulates seasonal reproduction in birds [7].
Arrestin-1 and arrestin-4, termed rod and cone arrestin, are expressed in photoreceptor cells and terminate rhodopsin and cone opsin signaling.
Color Vision: From Genes to Perception, chapter Opsin genes, cone photopigments, color vision, and color blindness, pages 3-51.