title: Inclusion Body Fusion of Human Parainfluenza Virus Type 3 Regulated by Acetylated α-Tubulin Enhances Viral Replication.
abstract: Viral inclusion bodies (IBs), or replication factories, are unique structures generated by viral proteins together with some cellular proteins as a platform for efficient viral replication, but little is known about the mechanism underlying IB formation and fusion. Our previous study demonstrated that the interaction between the nucleoprotein (N) and phosphoprotein (P) of human parainfluenza virus type 3 (HPIV3), an enveloped virus with great medical impact, can form IBs. In this study, we found that small IBs can fuse with each other to form large IBs that enhance viral replication. Furthermore, we found that acetylated α-tubulin interacts with the N-P complex and colocalizes with IBs of HPIV3 but does not interact with the N-P complex of human respiratory syncytial virus or vesicular stomatitis virus and does not colocalize with IBs of human respiratory syncytial virus. Most importantly, enhancement of α-tubulin acetylation using the pharmacological inhibitor trichostatin A (TSA), RNA interference (RNAi) knockdown of the deacetylase enzymes histone deacetylase 6 (HDAC6) and sirtuin 2 (SIRT2), or expression of α-tubulin acetyltransferase 1 (α-TAT1) resulted in the fusion of small IBs into large IBs and effective viral replication. In contrast, suppression of acetylation of α-tubulin by overexpressing HDAC6 and SIRT2 profoundly inhibited the fusion of small IBs and viral replication. Our findings offer previously unidentified mechanistic insights into the regulation of viral IB fusion by acetylated α-tubulin, which is critical for viral replication.
  
  
  OBJECTIVE
  Inclusion bodies (IBs) are unique structures generated by viral proteins and some cellular proteins as a platform for efficient viral replication. Human parainfluenza virus type 3 (HPIV3) is a nonsegmented single-stranded RNA virus that mainly causes lower respiratory tract disease in infants and young children. However, no vaccines or antiviral drugs for HPIV3 are available. Therefore, understanding virus-host interactions and developing new antiviral strategies are increasingly important. Acetylation on lysine (K) 40 of α-tubulin is an evolutionarily conserved modification and plays an important role in many cellular processes, but its role in viral IB dynamics has not been fully explored. To our knowledge, our findings are the first to show that acetylated α-tubulin enhances viral replication by regulating HPIV3 IB fusion.
authors.affiliation: State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, China.|Hubei University of Chinese Medicine, School of Laboratory Medicine, Wuhan, China.
authors.forename: Shengwei
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Yanliang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Virology and Modern Virology Research Center, College of Life Sciences, Wuhan University, Wuhan, China chenmz@whu.edu.cn.
authors.forename: Mingzhou
authors.initials: M
authors.lastname: Chen
mesh_terms: D000107:Acetylation; D002460:Cell Line; D015967:Gene Expression Regulation, Viral; D006801:Humans; D007181:Inclusion Bodies, Viral; D010224:Parainfluenza Virus 3, Human / Q000502:physiology*; D011485:Protein Binding; D012367:RNA, Viral / Q000096:biosynthesis; D010253:Respirovirus Infections / Q000378:metabolism* / Q000821:virology*; D014158:Transcription, Genetic; D014404:Tubulin / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
chemical_list: D012367:RNA, Viral; D014404:Tubulin; D014764:Viral Proteins
keywords: acetylated α-tubulin; human parainfluenza virus type 3; inclusion bodies