Integrin beta and receptor for activated protein kinase C are involved in the cell entry of Bombyx mori cypovirus

Self Cite

Bombyx mori cypovirus (BmCPV), a member of the Reoviridae, specifically infects silkworms and causes extensive economic losses to the sericulture industry. To date, the entry mechanism of BmCPV into cells is unclear. Here we used electron microscopy to study the route of entry of BmCPV into cells, and the results demonstrated that the entry of BmCPV into BmN cells was mediated by endocytosis. Blocking the entry pathway with four endocytosis inhibitors, including dansylcadaverine, chlorpromazine, genistein, and PP2, significantly decreased the infectivity of BmCPV. This indicates that BmCPV enters BmN cells via endocytosis, and that clathrin-mediated sorting is the predominant entry method. After the relative expression levels of clathrin heavy chain (clathrin, GenBank accession No. NM_001142971.1) and the adaptor protein complex-1 gamma subunit AP-1 (AP-1, GenBank accession No. JQ824201.1), which are involved in clathrin-mediated endocytosis, were inhibited by RNA interference or abolishing the functions of clathrin and AP-1 with their corresponding antibodies, the infectivity of BmCPV was reduced significantly, which suggests that clathrin-mediated endocytosis contributed to the entry of BmCPV into cells. Our findings suggest that the clathrin-mediated endocytosis pathway is a candidate for the development of therapeutics for silkworm cytoplasmic polyhedrosis.

Section: Resultsmentioning

confidence: 99%

Clathrin-mediated endocytosis is a candidate entry sorting mechanism for Bombyx mori cypovirus

Chen

Zhu

Zhang

et al. 2018

Self Cite

“…It suggests that VP5 sequesters RACK1 and VDAC2 in the apoptosis-inducing process 21 . Furthermore, together with integrin beta, RACK1 is involved in the cell entry of Bombyx mori cypovirus 22 . Additionally, RACK1 was discovered as one of the 16 interacting cellular proteins by the yeast two-hybrid system during a screen for classic swine fever virus (CSFV) NS5A interactive proteins in the cDNA library of the swine umbilical vein endothelial cell (SUVEC) 23 .…”

Section: Introductionmentioning

confidence: 99%

RACK1 is indispensable for porcine reproductive and respiratory syndrome virus replication and NF-κB activation in Marc-145 cells

Zhao

Zhu

et al. 2018

Porcine reproductive and respiratory syndrome virus (PRRSV) causes porcine reproductive and respiratory syndrome (PRRS), which is currently insufficiently controlled. RACK1 (receptor of activated protein C kinase 1) was first identified as a receptor for protein kinase C, with increasing evidence showing that the functionally conserved RACK1 plays important roles in cancer development, NF-κB activation and various virus infections. However, the roles of RACK1 during PRRSV infection in Marc-145 cells have not been described yet. Here we demonstrated that infection of Marc-145 cells with the highly pathogenic PRRSV strain YN-1 from our lab led to activation of NF-κB and upregulation of RACK1 expression. The siRNA knockdown of RACK1 inhibited PRRSV replication in Marc-145 cells, abrogated NF-κB activation induced by PRRSV infection and reduced the viral titer. Furthermore, knockdown of RACK1 could inhibit an ongoing PRRSV infection. We found that RACK1 is highly conserved across different species based on the phylogenetic analysis of mRNA and deduced amino acid sequences. Taken together, RACK1 plays an indispensable role for PRRSV replication in Marc-145 cells and NF-κB activation. The results would advance our further understanding of the molecular mechanisms underlying PRRSV infection in swine and indicate RACK1 as a promising potential therapeutic target.

“…(3) Autophagy is only slightly induced by BmCPV infection, and could not prevent the invasion and replication of the virus 11 . (4) Establishing a BmCPV infection depends on other factors interacting with integrin beta and receptor for activated protein kinase C (RACK1) to form a receptor complex for the entry of BmCPV 12 . Thus far, the molecular mechanism underlying the midgut infection of BmCPV and the antivirus immune response to BmCPV infection is not clearly understood due to the complexity in dsRNA virus infection.…”

Section: Introductionmentioning

confidence: 99%

DNA methylation in silkworm genome may provide insights into epigenetic regulation of response to Bombyx mori cypovirus infection

Jie

Shang

et al. 2017

DNA methylation is an important epigenetic modification that regulates a wide range of biological processes including immune response. However, information on the epigenetics-mediated immune mechanisms in insects is limited. Therefore, in this study, we examined transcriptomes and DNA methylomes in the fat body and midgut tissues of silkworm, Bombyx mori with or without B. mori cytoplasmic polyhedrosis virus (BmCPV) infection. The transcriptional profile and the genomic DNA methylation patterns in the midgut and fat body were tissue-specific and dynamically altered after BmCPV challenge. KEGG pathway analysis revealed that differentially methylated genes (DMGs) could be involved in pathways of RNA transport, RNA degradation, nucleotide excision repair, DNA replication, etc. 27 genes were shown to have both differential expression and differential methylation in the midgut and fat body of infected larvae, respectively, indicating that the BmCPV infection-induced expression changes of these genes could be mediated by variations in DNA methylation. BS-PCR validated the hypomethylation of G2/M phase-specific E3 ubiquitin-protein ligase-like gene in the BmCPV infected midgut. These results demonstrated that epigenetic regulation may play roles in host-virus interaction in silkworm and would be potential value for further studies on mechanism of BmCPV epithelial-specific infection and epigenetic regulation in the silkworm.