| First Author | Zako M | Year | 2002 |
| Journal | J Biol Chem | Volume | 277 |
| Issue | 28 | Pages | 25592-600 |
| PubMed ID | 11991949 | Mgi Jnum | J:77847 |
| Mgi Id | MGI:2182702 | Doi | 10.1074/jbc.M201279200 |
| Citation | Zako M, et al. (2002) Molecular cloning and characterization of chick sialoprotein associated with cones and rods, a developmentally regulated glycoprotein of interphotoreceptor matrix. J Biol Chem 277(28):25592-600 |
| abstractText | MY-174 is an IgM class monoclonal antibody originally established against chick PG-M/versican. The antibody specifically stains the photoreceptor layer, where we recently reported an absence of PG-M/versican. In this study, we re-characterized the antibody and identified the molecule that reacts to MY-174 at the photoreceptor layer. Immunohistochemistry localized the antigen to the matrix surrounding photoreceptors. A variety of glycosidase digestions showed that the antigen is the 150-kDa glycoprotein that has sialylated N- and O-linked glycoconjugates having a molecular mass of more than 30-kDa. The peptide sequences obtained from purified MY-174 antigen showed we had sequenced a full-length cDNA with an open reading frame of 2787 base pairs, encoding a polypeptide of 928 amino acids, with 56 and 54% identities to human and mouse sialoprotein associated with cones and rods (SPACRs), respectively, and with the structural features observed in SPACRs. The specific sialylated O-glycoconjugates here are involved in the epitope structure for MY-174. SPACR first appeared by embryonic days 15-16, and expression increased with developmental age, paralleling the adhesion between neural retina and retinal pigment epithelium. Thus, we concluded that the MY-174 antigen at the photoreceptor layer, a developmentally regulated glycoprotein, is identical to chick SPACR and may be involved in a novel system mediating adhesion between neural retina and retinal pigment epithelium. |
