Cloning of the cDNA for a novel photoreceptor membrane protein (rom-1) identifies a disk rim protein family implicated in human retinopathies.
The molecules essential to the continual morphogenesis and shedding of the opsin-containing disks of vertebrate photoreceptors are largely unknown. We describe a 37 kd protein, rom-1, which is 35% identical and structurally similar to peripherin/retinal degeneration slow (rds). Like peripherin, rom-1 is a retina-specific integral membrane protein localized to the photoreceptor disk rim. The two proteins are similarly oriented in the membrane, and each has a highly conserved (15/16 residues) cysteine- and proline-rich domain in the disk lumen. Although both rom-1 and peripherin form disulfide-linked dimers, they do not form heterodimers with each other, but appear to associate noncovalently. These results suggest both that rom-1 and peripherin are functionally related members of a new photoreceptor-specific protein family and that rom-1, like peripherin, is likely to be important to outer segment morphogenesis. The association of mutations in RDS with retinitis pigmentosa indicates that ROM1 is a strong candidate gene for human retinopathies.
Bascom
R A
RA
Department of Genetics, Hospital for Sick Children, Toronto, Ontario, Canada.
Manara
S
S
Collins
L
L
Molday
R S
RS
Kalnins
V I
VI
McInnes
R R
RR
D000328:Adult; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D006801:Humans; D007381:Intermediate Filament Proteins / Q000502:physiology; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D009479:Neuropeptides / Q000502:physiology; D009898:Optic Disk / Q000378:metabolism*; D064531:Peripherins; D010786:Photoreceptor Cells / Q000378:metabolism*; D012164:Retinal Diseases / Q000209:etiology*; D012374:Rod Cell Outer Segment / Q000378:metabolism
D001426:Bacterial Proteins; D007381:Intermediate Filament Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; C578994:PRPH protein, human; C578997:PRPH2 protein, human; D064531:Peripherins; C042833:ROM protein, Bacteria; D004247:DNA