Forrest J Craig, Campbell Jacquelyn A, Schelling Pierre, Stehle Thilo, Dermody Terence S
Department of Microbiology and Immunology, and Elizabeth B. Lamb Center for Pediatric Research, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
J Biol Chem. 2003 Nov 28;278(48):48434-44. doi: 10.1074/jbc.M305649200. Epub 2003 Sep 9.
Mammalian reoviruses are nonenveloped viruses with a long, filamentous attachment protein that dictates disease phenotypes following infection of newborn mice and is a structural homologue of the adenovirus attachment protein. Reoviruses use junctional adhesion molecule 1 (JAM1) as a serotype-independent cellular receptor. JAM1 is a broadly expressed immunoglobulin superfamily protein that forms stable homodimers and regulates tight-junction permeability and lymphocyte trafficking. We employed a series of structure-guided binding and infection experiments to define residues in human JAM1 (hJAM1) important for reovirus-receptor interactions and to gain insight into mechanisms of reovirus attachment. Binding and infection experiments using chimeric and domain deletion mutant receptor molecules indicate that the amino-terminal D1 domain of hJAM1 is required for reovirus attachment, infection, and replication. Reovirus binding to hJAM1 occurs more rapidly than homotypic hJAM1 association and is competed by excess hJAM1 in vitro and on cells. Cross-linking hJAM1 diminishes the capacity of reovirus to bind hJAM1 in vitro and on cells and negates the competitive effects of soluble hJAM1 on reovirus attachment. Finally, mutagenesis studies demonstrate that residues intimately associated with the hJAM1 dimer interface are critical for reovirus interactions with hJAM1. These results suggest that reovirus attachment disrupts hJAM1 dimers and highlight similarities between the attachment strategies of reovirus and adenovirus.
哺乳动物呼肠孤病毒是无包膜病毒，具有一种长丝状附着蛋白，该蛋白决定新生小鼠感染后的疾病表型，并且是腺病毒附着蛋白的结构同源物。呼肠孤病毒利用连接黏附分子1（JAM1）作为不依赖血清型的细胞受体。JAM1是一种广泛表达的免疫球蛋白超家族蛋白，可形成稳定的同型二聚体，并调节紧密连接通透性和淋巴细胞运输。我们进行了一系列基于结构的结合和感染实验，以确定人JAM1（hJAM1）中对呼肠孤病毒-受体相互作用重要的残基，并深入了解呼肠孤病毒附着机制。使用嵌合和结构域缺失突变受体分子的结合和感染实验表明，hJAM1的氨基末端D1结构域是呼肠孤病毒附着、感染和复制所必需的。呼肠孤病毒与hJAM1的结合比同型hJAM1缔合更快，并且在体外和细胞上会被过量的hJAM1竞争。交联hJAM1会降低呼肠孤病毒在体外和细胞上结合hJAM1的能力，并消除可溶性hJAM1对呼肠孤病毒附着的竞争作用。最后，诱变研究表明，与hJAM1二聚体界面密切相关的残基对于呼肠孤病毒与hJAM1的相互作用至关重要。这些结果表明，呼肠孤病毒附着会破坏hJAM1二聚体，并突出了呼肠孤病毒和腺病毒附着策略之间的相似性。
