Evidence for an association between heat shock protein 70 and the respiratory syncytial virus polymerase complex within lipid-raft membranes during virus infection

Abstract

In this report, the interaction between respiratory syncytial virus (RSV) and heat shock protein 70 (HSP70) was examined. Although no significant increase in total HSP70 protein levels was observed during virus infection, analysis of the HSP70 content in lipid-raft membranes from mock- and virus-infected cells revealed an increase in the levels of raft-associated HSP70 during virus infection. Fluorescence microscopy demonstrated that this transport of HSP70 into lipid-raft membranes correlated with the appearance of HSP70 within virus-induced inclusion bodies. Furthermore, co-localisation of HSP70 with the virus N protein and the raft lipid GM1 was observed within these structures. Immunoprecipitation experiments demonstrated the ability of HSP70 to interact with the virus polymerase complex in lipid-rafts in an ATP-dependent manner. Collectively, these data suggest that RSV may induce cellular changes which allow the recruitment of specific host-cell factors, via lipid-raft membranes, to the polymerase complex.

Hsp70 Protein Positively Regulates Rabies Virus Infection

“…complex. Indeed, previous studies of three paramyxoviruses, measles virus, canine distemper virus, and respiratory syncytial virus, have provided evidence for an interaction between the N protein and Hsp70 (3,29,30). In these cases, Hsp70 has been shown to stimulate viral polymerase in vitro activity, but it is not clear whether Hsp70 acts directly as a cofactor of the enzymatic process or whether it assists the folding of the N protein in an active form.…”

Differential Regulation of GM1 and Asialo-GM1 Expression by T Cells and Natural Killer (NK) Cells in Respiratory Syncytial Virus Infection

“…At the level of the virus life cycle, RSV replication machinery colocalizes with lipid rafts, and virions are selectively assembled at and likely bud from lipid rafts (50)(51)(52)(53)(54). GM1 is incorporated into the RSV viral envelope (55).…”

Role of Membrane Rafts in Viral Infection

“…Involvement of membrane rafts in viral RNA synthesis of enveloped viruses has been reported for HCV [143][144][145][146], respiratory syncytial virus (RSV; Paramyxoviridae) [147,148], DEN [149], and JEV [149]. Association of HCV nonstructural (NS) proteins with cholesterol-enriched membrane rafts in the Golgi-derived membrane forms the replication site of HCV RNA synthesis and protects it from RNase and protease [143,144].…”

“…The M protein is located between viral envelope and the RNP. The association of RSV RNP with membrane rafts leads to efficient RNA polymerase activity that may be required for interaction with the cellular factor HSP70, which is one of the virus receptor candidates, via membrane rafts in an ATP-dependent manner [147,148].…”

“…The role of membrane rafts in the assembly and budding of enveloped viruses has been investigated for influenza virus [59,63,[150][151][152][153][154][155][156][157][158][159][160], HIV-1 [63,[161][162][163][164][165][166][167][168][169][170][171][172][173], HTLV-1 [174], measles virus (Paramyxoviridae) [63,175,176], Sendai virus [Paramyxoviridae] [177,178], Newcastle disease virus (NDV; Paramyxoviridae) [179,180], RSV [147,148,[181][182][183][184], HSV [185,186], murine cytomegalovirus (MCMV; Herpesviridae) [187], Ebola virus [70,188], Marburg virus [70], and vesicular stomatitis virus (VSV; Rhabdoviridae) …”