Role of N-Linked Glycosylation of the 5-HT2A Receptor in JC Virus Infection
Role of N-Linked Glycosylation of the 5-HT2A Receptor in JC Virus Infection
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DOI：
10.1128/jvi.00978-10
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发表时间：
2010-10-01
影响因子：
5.4
通讯作者：
Atwood, Walter J.
中科院分区：
文献类型：
--
作者：
Maginnis, Melissa S.;Haley, Sheila A.;Atwood, Walter J.
JC病毒是一种人类多瘤病毒，是致死性脱髓鞘疾病进行性多灶性白质脑病(PML)的病原体。JCV对宿主细胞的感染依赖于与细胞表面天冬酰胺(N)连接的唾液酸和5-羟色胺(2A)受体(5HT(2A)R)的相互作用。5-HT2AR在细胞外N端含有5个潜在的N-连接糖基化位点。其他5-羟色胺受体的糖基化对于表达、配体结合和受体功能是必不可少的。此外，细胞受体的糖基化也被报道在JCV感染中起重要作用。因此，我们推测5-HT2AR N-连接的糖基化位点是JCV感染所必需的。用N-连接糖基化抑制剂衣霉素处理表达5-HT2AR的细胞，可减少JCV感染。5个N-连接糖基化位点的单独突变不影响5-HT2AR支持JCV感染的能力，也不改变该受体的细胞表面表达。然而，所有5个N-连接的糖基化位点的突变同时降低了5-HT2AR支持感染的能力，并改变了细胞表面的表达。同样，衣霉素处理降低了细胞表面5-HT2AR的表达。表达野生型5-HT2AR的细胞的所有五个N-连接糖基化位点的突变或衣霉素处理导致该受体的电泳迁移率改变。用PNGase F处理细胞，从细胞表面去除N-连接的寡糖，并不影响5-HT2AR表达细胞的JCV感染。这些数据证实了5-HT2AR作为JCV受体的重要性，并表明该受体的唾液酸成分与5-HT2AR没有直接联系。
JC virus (JCV) is a human polyomavirus and the causative agent of the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). JCV infection of host cells is dependent on interactions with cell surface asparagine (N)-linked sialic acids and the serotonin 5-hydroxytryptamine(2A) receptor (5HT(2A)R). The 5-HT2AR contains five potential N-linked glycosylation sites on the extracellular N terminus. Glycosylation of other serotonin receptors is essential for expression, ligand binding, and receptor function. Also, glycosylation of cellular receptors has been reported to be important for JCV infection. Therefore, we hypothesized that the 5-HT2AR N-linked glycosylation sites are required for JCV infection. Treatment of 5-HT2AR-expressing cells with tunicamycin, an inhibitor of N-linked glycosylation, reduced JCV infection. Individual mutation of each of the five N-linked glycosylation sites did not affect the capacity of 5-HT2AR to support JCV infection and did not alter the cell surface expression of the receptor. However, mutation of all five N-linked glycosylation sites simultaneously reduced the capacity of 5-HT2AR to support infection and altered the cell surface expression. Similarly, tunicamycin treatment reduced the cell surface expression of 5-HT2AR. Mutation of all five N-linked glycosylation sites or tunicamycin treatment of cells expressing wild-type 5-HT2AR resulted in an altered electrophoretic mobility profile of the receptor. Treatment of cells with PNGase F, to remove N-linked oligosaccharides from the cell surface, did not affect JCV infection in 5-HT2AR-expressing cells. These data affirm the importance of 5-HT2AR as a JCV receptor and demonstrate that the sialic acid component of the receptor is not directly linked to 5-HT2AR.