Negatively charged residues in the endodomain are critical for specific assembly of spike protein into murine coronavirus

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• 作者：Qianqian Yao^a ; Paul S. Masters^b ; Rong Ye^a ; ^{yerong24@fudan.edu.cn}
• 关键词：Coronavirus ; Spike glycoprotein ; Assembly ; Endodomain ; Negatively charged residues
• 刊名：Virology
• 出版年：2013
• 出版时间：20 July, 2013
• 年：2013
• 卷：442
• 期：1
• 页码：74-81
• 全文大小：7509 K

文摘

Coronavirus spike (S) protein assembles into virions via its carboxy-terminus, which is composed of a transmembrane domain and an endodomain. Here, the carboxy-terminal charge-rich motif in the endodomain was verified to be critical for the specificity of S assembly into mouse hepatitis virus (MHV). Recombinant MHVs exhibited a range of abilities to accommodate the homologous S endodomains from the betacoronaviruses bovine coronavirus and human SARS-associated coronavirus, the alphacoronavirus porcine transmissible gastroenteritis virus (TGEV), and the gammacoronavirus avian infectious bronchitis virus respectively. Interestingly, in TGEV endodomain chimeras the reverting mutations resulted in stronger S incorporation into virions, and a net gain of negatively charged residues in the charge-rich motif accounted for the improvement. Additionally, MHV S assembly could also be rescued by the acidic carboxy-terminal domain of the nucleocapsid protein. These results indicate an important role for negatively charged endodomain residues in the incorporation of MHV S protein into assembled virions.