Wick M J, Fan G, Loh H H
Department of Pharmacology, University of Minnesota Medical School, Minneapolis 55455, USA.
Brain Res Mol Brain Res. 1996 Mar;36(2):322-8. doi: 10.1016/0169-328x(95)00258-t.
Previously, our laboratory purified and isolated the cDNA for OBCAM (opioid binding cell adhesion molecule) from bovine brain, as well as highly homologous rat brain cDNA clones, SG13 and DUZ-1. Structural similarities with members of the immunoglobulin superfamily suggest a possible role for OBCAM in cell adhesion and recognition, while studies in our own laboratory suggest that OBCAM is important in the regulation of opioid binding and signal transduction. However, OBCAM lacks a putative transmembrane domain, and its possible mode of linkage to the cellular membrane has not been studied. Upon transfection of Cos 1 cells with SG13 and DUZ-1 cDNAs, the OBCAM-homologous proteins were expressed on the surface of the Cos 1 cells. These proteins were released from the membrane of the Cos 1 cells upon digestion with phosphatidylinositol-specific phospholipase C (PI-PLC), demonstrating that they are linked to the membrane via a phosphatidylinositol (PI) linkage. These results are consistent with a role for OBCAM in cell recognition and adhesion, as well as in cellular signaling.
此前，我们实验室从牛脑中纯化并分离出了阿片样物质结合细胞粘附分子（OBCAM）的cDNA，以及高度同源的大鼠脑cDNA克隆SG13和DUZ-1。与免疫球蛋白超家族成员的结构相似性表明，OBCAM可能在细胞粘附和识别中发挥作用，而我们实验室的研究表明，OBCAM在阿片样物质结合和信号转导的调节中很重要。然而，OBCAM缺乏推定的跨膜结构域，其与细胞膜的可能连接方式尚未得到研究。在用SG13和DUZ-1 cDNA转染Cos 1细胞后，OBCAM同源蛋白在Cos 1细胞表面表达。在用磷脂酰肌醇特异性磷脂酶C（PI-PLC）消化后，这些蛋白从Cos 1细胞膜上释放出来，表明它们通过磷脂酰肌醇（PI）连接与膜相连。这些结果与OBCAM在细胞识别、粘附以及细胞信号传导中的作用一致。
