Synthesis of interphotoreceptor retinoid-binding protein (IRBP) by monkey retina in organ culture: effect of monensin.
Whole monkey retinas were incubated in short-term organ culture with either radiolabeled amino acids or glucosamine. Soluble retinal proteins and proteins in the culture medium were analyzed by SDS-poly-acrylamide gel electrophoresis. Fluorography showed that the interphotoreceptor retinoid-binding protein (IRBP), a 146,000 Mr glycoprotein localized in the extracellular matrix, is synthesized by the neural retina and rapidly secreted into the medium. Secretion is blocked by 10-5M monensin. No significant IRBP synthesis was observed in the pigment-epithelium-choroid complex. IRBP is thus the major component synthesized and secreted by the neural retina into the interphotoreceptor space. This, and its affinity for retinoid makes it a prime candidate for an extracellular retinoid transport vehicle.
D000818:Animals; D005109:Extracellular Matrix / Q000378:metabolism; D005663:Furans / Q000494:pharmacology*; D005944:Glucosamine / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008715:Methionine / Q000378:metabolism; D008985:Monensin / Q000494:pharmacology*; D009924:Organ Culture Techniques; D010786:Photoreceptor Cells / Q000378:metabolism*; D012160:Retina / Q000187:drug effects / Q000378:metabolism*; D012177:Retinol-Binding Proteins / Q000096:biosynthesis*
D005663:Furans; D006023:Glycoproteins; D012177:Retinol-Binding Proteins; D008985:Monensin; D008715:Methionine; D005944:Glucosamine