THE CDNA RPE1 AND MONOCLONAL ANTIBODY-HMB-50 DEFINE GENE-PRODUCTS PREFERENTIALLY EXPRESSED IN RETINAL-PIGMENT EPITHELIUM

As a first step towards identifying genes expressed specifically in the retinal pigment epithelium (RPE), we generated a bovine RPE cDNA library. In preliminary characterization of this library, we isolated a clone, RPE1, that was identified as the bovine homologue of a human cDNA thought to encode the HMB-50 melanoma antigen. Sequence analysis suggests RPE1 encodes a membrane-anchored glycoprotein. In Northern blot analysis of RNA from bovine tissues, the 2·5 kb RPE1 transcript was detected only in the RPE. Southern blot analysis suggested the presence of a single bovine rpe1 gene. In normal human eyes. HMB-50 immunoreactivity was also restricted to the RPE; no immunoreactivity was detected in other intraocular pigmented cells. Thus, RPE1 and HMB-50 define gene products preferentially expressed in the RPE at the RNA and protein levels, respectively. © 1992.