title: The ocular albinism type 1 gene product is an N-glycoprotein but glycosylation is not required for its subcellular distribution.
abstract: The ocular albinism type 1 (OA1) gene product is a membrane glycoprotein that may play a role in controlling melanosome growth and maturation. A number of mutations in the OA1 gene lead to ocular albinism due at least in part to retention of the aberrant protein in the endoplasmic reticulum. To examine whether N-glycosylation plays a role in the post-translational trafficking of the Oa1 protein, we constructed a series of mutant mouse Oa1 cDNAs encoding an Oa1-green fluorescent protein fusion in which some or all of the potential glycosylation sites were eliminated by site-directed mutagenesis. Biochemical studies in transfected cells treated with tunicamycin and peptide:N-glycosidase F suggest that asparagine at amino acid 106 is essential for N-glycosylation of the protein. Mutation at amino acid 106 that eliminated glycosylation did not affect the endo/lysosomal distribution of the Oa1 protein in either COS cells or cultured murine melanocytes.
authors.affiliation: The Ronald O. Perelman Department of Dermatology, NYU School of Medicine, New York, New York 10016, USA.
authors.forename: B
authors.initials: B
authors.lastname: Shen
authors.forename: S J
authors.initials: SJ
authors.lastname: Orlow
mesh_terms: D016117:Albinism, Ocular / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D019556:COS Cells; D002451:Cell Compartmentation / Q000235:genetics*; D002461:Cell Line, Transformed; D022162:Cytoplasmic Vesicles / Q000235:genetics / Q000378:metabolism; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism*; D006031:Glycosylation; D049452:Green Fluorescent Proteins; D006801:Humans; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D051907:Lysosomal Membrane Proteins; D008247:Lysosomes / Q000235:genetics / Q000378:metabolism; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D021381:Protein Transport / Q000235:genetics; D012160:Retina / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D017386:Sequence Homology, Amino Acid; D014162:Transfection
chemical_list: D015703:Antigens, CD; D005136:Eye Proteins; C095276:GPR143 protein, human; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D049452:Green Fluorescent Proteins