Zhong Xiaotian, Kriz Ron, Seehra Jasbir, Kumar Ravindra
Department of Chemical and Screening Sciences, Wyeth Research, 85 Bolton Street, Cambridge, MA 02140, USA.
FEBS Lett. 2004 Mar 26;562(1-3):111-7. doi: 10.1016/S0014-5793(04)00191-7.
P(2)Y(12) receptor is a G(i)-coupled adenosine diphosphate (ADP) receptor with a critical role in platelet aggregation. It contains two potential N-linked glycosylation sites at its extra cellular amino-terminus, which may modulate its activity. Studies of both tunicamycin treatment and site-directed mutagenesis have revealed a dispensable role of the N-linked glycosylation in the receptor's surface expression and ligand binding activity. However, the non-glycosylated P(2)Y(12) receptor is defective in the P(2)Y(12)-mediated inhibition of the adenylyl cyclase activity. Thus the study uncovers an unexpected vital role of N-linked glycans in receptor's signal transducing step but not in surface expression or ligand binding.
P(2)Y(12)受体是一种与G(i)偶联的二磷酸腺苷（ADP）受体，在血小板聚集中起关键作用。它在细胞外氨基末端含有两个潜在的N-连接糖基化位点，这可能会调节其活性。衣霉素处理和定点诱变研究均表明，N-连接糖基化在受体的表面表达和配体结合活性中起非必需作用。然而，非糖基化的P(2)Y(12)受体在P(2)Y(12)介导的腺苷酸环化酶活性抑制方面存在缺陷。因此，该研究揭示了N-连接聚糖在受体信号转导步骤中而非表面表达或配体结合中具有意想不到的重要作用。
