Identification of a New Sprouty Protein Responsible for the Inhibition of the Bombyx mori Nucleopolyhedrovirus Reproduction

Abstract

The rat sarcoma-extracellular signal regulated kinase mitogen-activated protein kinases pathway, one of the most ancient signaling pathways, is crucial for the defense against Bombyx mori nucleopolyhedrovirus (BmNPV) infection. Sprouty (Spry) proteins can inhibit the activity of this pathway by receptor tyrosine kinases. We cloned and identified a new B. mori gene with a Spry domain similar to the Spry proteins of other organisms, such as fruitfly, mouse, human, chicken, Xenopus and zebrafish, and named it BmSpry. The gene expression analysis showed that BmSpry was transcribed in all of the examined tissues and in all developmental stages from embryo to adult. BmSpry also induced expression of BmNPV in the cells. Our results indicated: (1) the knock-down of BmSpry led to increased BmNPV replication and silkworm larvae mortality; (2) over-expression of BmSpry led to reduced BmNPV replication; and (3) BmSpry regulated the activation of ERK and inhibited BmNPV replication. These results showed that BmSpry plays a crucial role in the antiviral defense of the silkworm both in vitro and in vivo.

A novel Lozenge gene in silkworm, Bombyx mori regulates the melanization response of hemolymph

“…The BmLz full length cDNA was amplified by PCR using Dazao (p50) hemocyte cDNA template, and digested with BamH I and ligated into pSL1180-A4-SV40-EGFP vector (Jin et al, 2014). 2 Â 10 5 BmE cells and S2 cells were seeded into 24-well plates for 24 h, and transiently transfected with pSL1180-A4-SV40-EGFP-BmLz using XtremeGENE HP DNA Transfection Reagent (Roche).…”

Comparative proteomic analysis of hemolymph proteins from Autographa californica multiple nucleopolyhedrovirus (AcMNPV)-sensitive or -resistant silkworm strains during infections

“…In the case of NPVs, no RNAi pathway proteins from Lepidopteran insects have been reported as suppressors limiting viral replications. Interestingly, emerging research shows that potential host factors are also involved in recognition/replication of NPVs (Terenius, 2008;Kang et al, 2011;Jiang et al, 2012;Lü et al, 2013;Turkki et al, 2013;Makkonen et al, 2013;Jin et al, 2014). However, factors affecting host cell permissiveness to BV infection/transduction remain largely unknown.…”

Identification of a PP2A gene in Bombyx mori with antiviral function against B. mori nucleopolyhedrovirus

“…Until now, many silkworm endogenous proteins have been identified to be involved in BmNPV infection. Nicotinamide adenine dinucleotide oxidoreductase‐like protein, BmLipase‐1 (Bmlip‐1), serine protease‐2 (SP‐2), Sprouty Protein, and Bmthymosin inhibit the multiplication and replication of BmNPV (Jin et al ., ; Cheng et al ., ; Liao et al ., ). PP2A acts as a protein phosphatase and participates in many intracellular physiological activities (Guergnon et al ., ).…”