21. They have similarities to vertebrate rhodopsins , the pigments that sense light in the retina. 22. The transmembrane part is highly homologous with other members of the rhodopsin family of GPCRs. 23. Mutations in rhodopsin kinase are associated with a form of night blindness called Oguchi disease. 24. See Rhodopsin for how night vision works. 25. Similarly, the K296E rhodopsin is observed to bind the visual arrestin with high affinity. 26. Mutation of the rhodopsin gene is a major contributor to various retinopathies such as retinitis pigmentosa. 27. This is called bleaching because the purified rhodopsin changes from violet to colorless in the light. 28. Bacteriorhodopsin belongs to the microbial rhodopsins . 29. The main target genes of PNR are rhodopsin and several opsins which are essential for sight. 30. The way this system operates was shown in animal model that have a mutant rhodopsin gene.
