Cone arrestin: deciphering the structure and functions of arrestin 4 in vision.

摘要: Cone arrestin (Arr4) was discovered 20 years ago as a human X-chromosomal gene that is highly expressed in pinealocytes and cone photoreceptors. Subsequently, specific antibodies were developed to identify Arr4 distinguish photoreceptor morphology health disease states. These reagents used demonstrate translocation from inner segments the dark outer with light stimulation, similarly Arrestin 1 (Arr1) rod A decade later, crystal structure solved, which provided more clues about Arr4’s mechanisms of action. With creation genetically engineered visual knockout mice, one critical function clarified. In single living cones, both arrestins bind light-activated, G protein receptor kinase (Grk1) phosphorylated opsins desensitize them, their absence, mouse pigment shutoff delayed. Still under investigation are additional functions; however, it clear has non-opsin-binding partners diverse synaptic roles, including cellular anchoring trafficking. Recent studies reveal involved high temporal resolution contrast sensitivity, opens up new direction for research on this intriguing protein. Even exciting potential therapeutic use promoter an AAV-halorhodopsin shown be effective using remaining cones retinal degeneration models drive circuitry motion detection light/dark discrimination.