Ocular albinism 1 protein: trafficking and function when expressed in Saccharomyces cerevisiae.
The ocular albinism 1 (Oa1) protein is believed to be involved in the biogenesis of melanosomes, but its cellular localization is controversial and its function is unknown. Based upon sequence homology, it has been predicted that Oa1 belongs to the G protein coupled receptor (GPCR) superfamily. We used the yeast Saccharomyces cerevisiae as a genetically amenable system to study the localization and function of Oa1. Sucrose gradient and immunofluorescence studies revealed that when expressed in yeast, Oa1 localizes to the prevacuolar compartment, the functional equivalent of the mammalian late endosome. Oa1 behaved as G protein coupled receptor in a yeast-based GPCR signalling assay. Extracts of cultured melanocytes, and, in particular, a particulate fraction from cultured melanocytes, stimulated Oa1-mediated GPCR signalling.
Staleva
Liliana
L
Department of Dermatology, New York University School of Medicine, 560 First Avenue, New York, NY 10016, USA.
Orlow
Seth J
SJ
D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D011992:Endosomes / Q000378:metabolism; D005136:Eye Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D018014:Gene Transfer Techniques; D006801:Humans; D008544:Melanocytes / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D013268:Stimulation, Chemical
D017077:Culture Media, Conditioned; D005136:Eye Proteins; C095276:GPR143 protein, human; D008562:Membrane Glycoproteins; D043562:Receptors, G-Protein-Coupled