| abstract |
long wave-sensitive opsins, member of the class A family of seven-transmembrane G protein-coupled receptors. Long Wave-Sensitive opsin is also called red-sensitive opsin or red cone photoreceptor pigment, which mediates visual transduction in response to light at long wavelengths. Vertebrate cone opsins are expressed in cone photoreceptor cells of the retina and involved in mediating photopic vision, which allows color perception. The cone opsins can be classified into four classes according to their peak absorption wavelengths: SWS1 (ultraviolet sensitive), SWS2 (short wave-sensitive), MWS/LWS (medium/long wave-sensitive), and RH2 (medium wave-sensitive, rhodopsin-like opsins). Members of this group belong to the class A of the G protein-coupled receptors and possess seven-transmembrane (TM) alpha-helices interconnected by three extracellular and three intracellular loops. |