Xing Liu, Fang Li, Jiwen Zhang, Lulu Wang, Jinliang Wang, Zhiyuan Wen, Zilong Wang, Lei Shuai , Xijun Wang , Jinying Ge, Dongming Zhao, Zhigao Bu

J Biol Chem.2020 Nov 18;jbc.RA120.014190.doi: 10.1074/jbc.RA120.014190. Online ahead of print.

Abstract

Rabies virus (RABV) matrix protein (M) plays crucial roles in viral transcription, replication, assembly, and budding; however, its function during the early stage of virus replication remains unknown. Here, we mapped the protein interactome between RABV M and human host factors using a proteomic approach, finding a link to the V-type proton ATPase (V-ATPase) catalytic subunit A (ATP6V1A) which is located in the endosomes where RABV first enters. By downregulating or upregulating ATP6V1A expression in HEK293T cells, we found that ATP6V1A facilitated RABV replication. We further found that ATP6V1A was involved in the dissociation of incoming viral M proteins during viral uncoating. Co-immunoprecipitation demonstrated that M interacted with the full length or middle domain of ATP6V1A, which was dependent on the lysine residue at position 256 and the glutamic acid residue at position 279. RABV growth and uncoating in ATP6V1A-depleted cells was restored by trans-complementation with the full length or interaction domain of ATP6V1A. Moreover, stably overexpressed ATP6V1A enhanced RABV growth in Vero cells which are used for the production of rabies vaccine. Our findings identify a new partner for RABV M proteins and establish a new role of ATP6V1A by promoting virion uncoating during RABV replication.

Keywords: ATP6V1A; RNA interference (RNAi); Rabies virus; confocal microscopy; matrix protein; protein-protein interaction; uncoating; vacuolar ATPase; vacuolar acidification; viral replication.

Published under license by The American Society for Biochemistry and Molecular Biology, Inc.