Characterisation of Structural Proteins from Chronic Bee Paralysis Virus (CBPV) Using Mass Spectrometry.

Aurore Chevin,Bruno Coutard,Magali Ribière-Chabert,Philippe Blanchard,Anne-Sophie Dabert-Gay,Richard Thiéry

doi:10.3390/v7062774

Abstract

Chronic bee paralysis virus (CBPV) is the etiological agent of chronic paralysis, an infectious and contagious disease in adult honeybees. CBPV is a positive single-stranded RNA virus which contains two major viral RNA fragments. RNA 1 (3674 nt) and RNA 2 (2305 nt) encode three and four putative open reading frames (ORFs), respectively. RNA 1 is thought to encode the viral RNA-dependent RNA polymerase (RdRp) since the amino acid sequence derived from ORF 3 shares similarities with the RdRP of families Nodaviridae and Tombusviridae. The genomic organization of CBPV and in silico analyses have suggested that RNA 1 encodes non-structural proteins, while RNA 2 encodes structural proteins, which are probably encoded by ORFs 2 and 3. In this study, purified CBPV particles were used to characterize virion proteins by mass spectrometry. Several polypeptides corresponding to proteins encoded by ORF 2 and 3 on RNA 2 were detected. Their role in the formation of the viral capsid is discussed.

Highlights

Chronic paralysis is an infectious and contagious disease of adult honeybees (Apis mellifera L.).It is known to induce a cluster of clinical signs, such as trembling and flightless bees crawling at the hive entrance [1]
We examined a chronic bee paralysis virus (CBPV) preparation from honeybee heads that was purified on a sucrose gradient, followed by SDS-Page separation and nano-HPLC coupled to a matrix-assisted laser desorption/ionization-time of flight/time of flight (MALDI-TOF/TOF) mass spectrometer
Anti-RNA-dependent RNA polymerase (RdRp) antibodies recognize the recombinant protein corresponding to the fragment of RdRp used for rabbit immunization, RdRp was not detected in the purified CBPV sample (Figure 2A)

Summary

Introduction

Chronic paralysis is an infectious and contagious disease of adult honeybees (Apis mellifera L.). It is known to induce a cluster of clinical signs, such as trembling and flightless bees crawling at the hive entrance [1]. The viral agent that causes this disease is the chronic bee paralysis virus (CBPV). CBPV shows neurotropism in concomitance with observed clinical signs [2]. The viral particle is anisometric and non-enveloped, its size being about 30–60 nm in length and 20 nm in width [3]. CBPV is a positive single-stranded fragmented RNA virus; its genome is composed of two major RNA fragments that have been completely sequenced, RNA 1 (3674 nt) and RNA 2 (2305 nt) [4]

Methods

Results

Conclusion