Wang Mingyang, Veit Michael
Institute of Virology, Veterinary Medicine, Free University Berlin, Berlin, Germany.
Protein Cell. 2016 Jan;7(1):28-45. doi: 10.1007/s13238-015-0193-x. Epub 2015 Jul 28.
Influenza C virus, a member of the Orthomyxoviridae family, causes flu-like disease but typically only with mild symptoms. Humans are the main reservoir of the virus, but it also infects pigs and dogs. Very recently, influenza C-like viruses were isolated from pigs and cattle that differ from classical influenza C virus and might constitute a new influenza virus genus. Influenza C virus is unique since it contains only one spike protein, the hemagglutinin-esterase-fusion glycoprotein HEF that possesses receptor binding, receptor destroying and membrane fusion activities, thus combining the functions of Hemagglutinin (HA) and Neuraminidase (NA) of influenza A and B viruses. Here we briefly review the epidemiology and pathology of the virus and the morphology of virus particles and their genome. The main focus is on the structure of the HEF protein as well as on its co- and post-translational modification, such as N-glycosylation, disulfide bond formation, S-acylation and proteolytic cleavage into HEF1 and HEF2 subunits. Finally, we describe the functions of HEF: receptor binding, esterase activity and membrane fusion.
丙型流感病毒是正黏病毒科的成员之一，可引起类似流感的疾病，但通常症状较轻。人类是该病毒的主要宿主，不过它也会感染猪和狗。最近，从猪和牛身上分离出了与经典丙型流感病毒不同的类似丙型流感病毒，它们可能构成一个新的流感病毒属。丙型流感病毒很独特，因为它仅含有一种刺突蛋白，即血凝素 - 酯酶 - 融合糖蛋白HEF，该蛋白具有受体结合、受体破坏和膜融合活性，因此兼具甲型和乙型流感病毒血凝素（HA）和神经氨酸酶（NA）的功能。在此，我们简要回顾该病毒的流行病学、病理学以及病毒粒子及其基因组的形态。主要关注点在于HEF蛋白的结构及其共翻译和翻译后修饰，如N - 糖基化、二硫键形成、S - 酰化以及蛋白水解切割成HEF1和HEF2亚基。最后，我们描述HEF的功能：受体结合、酯酶活性和膜融合。
