Further Characterization of Human Mucin-Like Glycoprotein Associated with Photoreceptor Cells by Its Introduction into Y79 Retinoblastoma Cells

Abstract

Purpose: To understand the function of a mucin- like glycoprotein associated with photoreceptor cells (MLGAPC), MLGAPC-transfected Y79 retinoblastoma cells were analyzed biochemically and morphologically. Methods: The cDNA for the core protein of human MLGAPC was isolated, cloned into a mammalian expression vector, pCAGGSneo, and then transfected into Y79 retinoblastoma cells. The cells and the medium were analyzed by means of Western blotting, and the morphology of the transfectants and parental cells was compared. Results: Western blot analysis of the culture medium revealed that the transfectants secreted MLGAPC into the medium. Lectin blot analysis of MLGAPC in the medium showed that it had a binding site for Maackia amurensis lectin II. No morphological difference was detected between the transfectants and parental cells. Conclusions: As expected from the deduced amino acid sequence of MLGAPC, it was secreted into the medium. The secreted MLGAPC was found to carry sialoglycans (rod type). The expression of MLGAPC had no effect on the adhesion or morphology of the cultured cells, which suggests that its interaction with other components may be required for these effects.

Differential Binding to Glycotopes Among the Layers of Three Mammalian Retinal Neurons by Man-Containing N-linked Glycan, Tα (Galβ1–3GalNAcα1-), Tn (GalNAcα1-Ser/Thr) and Iβ/IIβ (Galβ1–3/4GlcNAcβ-) Reactive Lectins

“…Therefore, glycoconjugates on the IPM-related structures and their exfoliate substances which undergoes glycosylation change during RD could be a good marker predicting the prognosis of the disease or the mediators facilitating the progression of this disease. In addition, carbohydrate also plays some role during retinal development in the embryonic stage [37], and also involves pathologic conditions of the eye such as age-related macular degeneration [38], and retinoblastoma [39]. The knowledge of the carbohydrate in the retina may help elucidate the pathogenesis of those diseases.…”