The Matrix Protein of Human Parainfluenza Virus Type 3 Induces Mitophagy that Suppresses Interferon Responses

The matrix (M) proteins of paramyxoviruses bind to the nucleocapsids and cytoplasmic tails of glycoproteins, thus mediating the assembly and budding of virions. We first determined the budding characterization of the HPIV3 Fusion (F) protein to investigate the assembly mechanism of human parainfluenza virus type 3 (HPIV3). Our results show that expression of the HPIV3 F protein alone is sufficient to initiate the release of virus-like particles (VLPs), and the F protein can regulate the VLP-forming ability of the M protein. Furthermore, HPIV3F-Flag, which is a recombinant HPIV3 with a Flag tag at the C-terminus of the F protein, was constructed and recovered. We found that the M, F, and hemagglutinin-neuraminidase (HN) proteins and the viral genome can accumulate in lipid rafts in HPIV3F-Flag-infected cells, and the F protein mainly exists in the form of F1 in VLPs, lipid rafts, and purified virions. Furthermore, the function of cholesterol in the viral envelope and cell membrane was assessed via the elimination of cholesterol by methyl-β-cyclodextrin (MβCD). Our results suggest that the infectivity of HPIV3 was markedly reduced, due to defective internalization ability in the absence of cholesterol. These results reveal that HPIV3 might assemble in the lipid rafts to acquire cholesterol for the envelope of HPIV3, which suggests the that disruption of the cholesterol composition of HPIV3 virions might be a useful method for the design of anti-HPIV3 therapy.

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Human Parainfluenza Virus Type 3 Matrix Protein Reduces Viral RNA Synthesis of HPIV3 by Regulating Inclusion Body Formation

Viruses ◽

10.3390/v10030125 ◽

2018 ◽

Vol 10 (3) ◽

pp. 125 ◽

Cited By ~ 2

Author(s):

Shengwei Zhang ◽

Qi Cheng ◽

Chenxi Luo ◽

Yali Qin ◽

Mingzhou Chen

Keyword(s):

Inclusion Body ◽

Virus Type ◽

Rna Synthesis ◽

Matrix Protein ◽

Viral Rna ◽

Parainfluenza Virus ◽

Body Formation ◽

Inclusion Body Formation ◽

Human Parainfluenza Virus ◽

Type 3

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Interaction of Human Parainfluenza Virus Type 3 Nucleoprotein with Matrix Protein Mediates Internal Viral Protein Assembly

Journal of Virology ◽

10.1128/jvi.02324-15 ◽

2015 ◽

Vol 90 (5) ◽

pp. 2306-2315 ◽

Cited By ~ 8

Author(s):

Guangyuan Zhang ◽

Yi Zhong ◽

Yali Qin ◽

Mingzhou Chen

Keyword(s):

Virus Type ◽

Matrix Protein ◽

Viral Proteins ◽

Parainfluenza Virus ◽

M Protein ◽

Content Type ◽

Virion Assembly ◽

Nucleoprotein N ◽

Human Parainfluenza Virus ◽

Type 3

ABSTRACTHuman parainfluenza virus type 3 (HPIV3) belongs to theParamyxoviridaefamily. Its three internal viral proteins, the nucleoprotein (N), the phosphoprotein (P), and the polymerase (L), form the ribonucleoprotein (RNP) complex, which encapsidates the viral genome and associates with the matrix protein (M) for virion assembly. We previously showed that the M protein expressed alone is sufficient to assemble and release virus-like particles (VLPs) and a mutant with the L305A point mutation in the M protein (ML305A) has a VLP formation ability similar to that of wild-type M protein. In addition, recombinant HPIV3 (rHPIV3) containing the ML305Amutation (rHPIV3-ML305A) could be successfully recovered. In the present study, we found that the titer of rHPIV3-ML305Awas at least 10-fold lower than the titer of rHPIV3. Using VLP incorporation and coimmunoprecipitation assays, we found that VLPs expressing the M protein (M-VLPs) can efficiently incorporate N and P via an N-M or P-M interaction and ML305A-VLPs had an ability to incorporate P via a P-M interaction similar to that of M-VLPs but were unable to incorporate N and no longer interacted with N. Furthermore, we found that the incorporation of P into ML305A-VLPs but not M-VLPs was inhibited in the presence of N. In addition, we provide evidence that the C-terminal region of P is involved in its interaction with both N and M and N binding to the C-terminal region of P inhibits the incorporation of P into ML305A-VLPs. Our findings provide new molecular details to support the idea that the N-M interaction and not the P-M interaction is critical for packaging N and P into infectious viral particles.IMPORTANCEHuman parainfluenza virus type 3 (HPIV3) is a nonsegmented, negative-sense, single-stranded RNA virus that belongs to theParamyxoviridaefamily and can cause lower respiratory tract infections in infants and young children as well as elderly or immunocompromised individuals. However, no effective vaccine has been developed or licensed. We used virus-like particle (VLP) incorporation and coimmunoprecipitation assays to determine how the M protein assembles internal viral proteins. We demonstrate that both nucleoprotein (N) and phosphoprotein (P) can incorporate into M-VLPs and N inhibits the M-P interaction via the binding of N to the C terminus of P. We also provide additional evidence that the N-M interaction but not the P-M interaction is critical for the regulation of HPIV3 assembly. Our studies provide a more complete characterization of HPIV3 virion assembly and substantiation that N interaction with M regulates internal viral organization.

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