title: Cell Cycle-independent Role of Cyclin D3 in Host Restriction of Influenza Virus Infection.
abstract: To identify new host factors that modulate the replication of influenza A virus, we performed a yeast two-hybrid screen using the cytoplasmic tail of matrix protein 2 from the highly pathogenic H5N1 strain. The screen revealed a high-score interaction with cyclin D3, a key regulator of cell cycle early G1phase. M2-cyclin D3 interaction was validated through GST pull-down and recapitulated in influenza A/WSN/33-infected cells. Knockdown ofCcnd3by small interfering RNA significantly enhanced virus progeny titers in cell culture supernatants. Interestingly, the increase in virus production was due to cyclin D3 deficiencyper seand not merely a consequence of cell cycle deregulation. A combined knockdown ofCcnd3andRb1, which rescued cell cycle progression into S phase, failed to normalize virus production. Infection by influenza A virus triggered redistribution of cyclin D3 from the nucleus to the cytoplasm, followed by its proteasomal degradation. When overexpressed in HEK 293T cells, cyclin D3 impaired binding of M2 with M1, which is essential for proper assembly of progeny virions, lending further support to its role as a putative restriction factor. Our study describes the identification and characterization of cyclin D3 as a novel interactor of influenza A virus M2 protein. We hypothesize that competitive inhibition of M1-M2 interaction by cyclin D3 impairs infectious virion formation and results in attenuated virus production. In addition, we provide mechanistic insights into the dynamic interplay of influenza virus with the host cell cycle machinery during infection.
authors.affiliation: From the HKU-Pasteur Research Pole and.|Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.|the Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 4HN, Scotland, United Kingdom.
authors.forename: Ying
authors.initials: Y
authors.lastname: Fan
authors.affiliation: From the HKU-Pasteur Research Pole and.|Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.
authors.forename: Chris Ka-Pun
authors.initials: CK
authors.lastname: Mok
authors.affiliation: Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.
authors.forename: Michael Chi Wai
authors.initials: MC
authors.lastname: Chan
authors.affiliation: From the HKU-Pasteur Research Pole and.|Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.|the Harbin Institute of Technology, Shenzhen Graduate School, Shenzhen, Guangdong 518055, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: From the HKU-Pasteur Research Pole and.|Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.|the Division of Biosciences, College of Health and Life Sciences, Brunel University London, London UB8 3PH, United Kingdom.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Nal
authors.affiliation: From the HKU-Pasteur Research Pole and.|Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.|Ksilink, French-German Advanced Translational Center, Strasbourg 67000, France, and.
authors.forename: François
authors.initials: F
authors.lastname: Kien
authors.affiliation: From the HKU-Pasteur Research Pole and bruzzone@hku.hk.|Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.|the Department of Cell Biology and Infection, Institut Pasteur, Paris Cedex 75015, France.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bruzzone
authors.affiliation: From the HKU-Pasteur Research Pole and sanyal@hku.hk.|Centre of Influenza Research, School of Public Health, LKS Faculty of Medicine, University of Hong Kong, Hong Kong SAR, China.
authors.forename: Sumana
authors.initials: S
authors.lastname: Sanyal
mesh_terms: D059447:Cell Cycle Checkpoints; D002460:Cell Line; D056743:Cyclin D3 / Q000378:metabolism*; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000502:physiology*; D007251:Influenza, Human / Q000378:metabolism* / Q000473:pathology; D060066:Protein Interaction Maps; D059748:Proteolysis; D014763:Viral Matrix Proteins / Q000378:metabolism*; D000086082:Viroporin Proteins
chemical_list: D056743:Cyclin D3; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins
keywords: G1/S cyclin; M2; cell cycle; cell cycle arrest; cyclin D3; influenza; protein degradation; protein-protein interaction; restriction factor