CHARACTERIZATION OF LAMPREY RHODOPSIN BY ISOLATION FROM LAMPREY RETINA AND EXPRESSION IN MAMMALIAN-CELLS

A visual pigment was extracted from lamprey retina and was expressed i n cultured mammalian cells (293S) using a cDNA fragment isolated from lamprey retina. The extracted pigment, a putative lamprey rhodopsin, h ad an absorption maximum at 503 nm. The recombinant lamprey rhodopsin, reconstituted with 11-cis-retinal, showed an absorption maximum at ab out 500 nm. Both pigments reacted with an anti-bovine rhodopsin antibo dy (Rh29), which recognizes the short photoreceptor cells in lamprey r etina. Unlike rhodopsins of higher vertebrates, the lamprey rhodopsin bleached gradually in the presence of 100 mM hydroxylamine even in the dark. Our results suggest that, despite its high similarities with ot her vertebrate rhodopsins, lamprey rhodopsin has a character different from those of higher vertebrates.