| First Author | Samaraweera P | Year | 2001 |
| Journal | Exp Eye Res | Volume | 72 |
| Issue | 3 | Pages | 319-29 |
| PubMed ID | 11180981 | Mgi Jnum | J:67790 |
| Mgi Id | MGI:1931402 | Doi | 10.1006/exer.2000.0962 |
| Citation | Samaraweera P, et al. (2001) The Mouse Ocular Albinism 1 Gene Product is an Endolysosomal Protein. Exp Eye Res 72(3):319-29 |
| abstractText | To gain insight into the role of Oa1, the mouse homolog of the human X-linked ocular albinism 1 protein, its properties and subcellular localization were investigated. Antiserum raised against an expressed segment of the Oa1 protein recognized a band of approximately 48 kDa in immunoblots of extracts of cultured mouse melan-a melanocytes, but not of cells of non-melanocyte origin. When melanocyte extracts were treated with glycopeptidase F, a approximately 44 kDa band appeared. Like the melanogenic enzyme tyrosinase, expression of Oa1 was stimulated by alpha-melanocyte stimulating hormone and inhibited by agouti signal protein. Upon density gradient centrifugation of organelles of melan-a cells, Oa1 protein colocalized with the late endosomal/lysosomal marker Lamp1, but only partial overlap was observed with melanosomal proteins in the high density region of the gradient. Immunofluorescence staining revealed that neither endogenous Oa1 nor an Oa1-green fluorescent protein fusion product colocalized with the melanosomal protein tyrosinase related protein-1 in the cell periphery. In contrast, colocalization of Oa1 and Oa1-green fluorescent protein fusion product with Lamp1 was extensive throughout the cell. These results indicate that Oa1 is a melanocyte-specific integral membrane glycoprotein localized to late endosomes/lysosomes but not mature melanosomes. Considering the microscopic findings in patients with X-linked ocular albinism 1, we speculate that Oa1 may play a role in the trafficking of vesicles to developing melanosomes. Copyright 2001 Academic Press. |
