Proteomic analysis of purified coronavirus infectious bronchitis virus particles

Abstract

BackgroundInfectious bronchitis virus (IBV) is the coronavirus of domestic chickens causing major economic losses to the poultry industry. Because of the complexity of the IBV life cycle and the small number of viral structural proteins, important virus-host relationships likely remain to be discovered. Toward this goal, we performed two-dimensional gel electrophoresis fractionation coupled to mass spectrometry identification approaches to perform a comprehensive proteomic analysis of purified IBV particles.ResultsApart from the virus-encoded structural proteins, we detected 60 host proteins in the purified virions which can be grouped into several functional categories including intracellular trafficking proteins (20%), molecular chaperone (18%), macromolcular biosynthesis proteins (17%), cytoskeletal proteins (15%), signal transport proteins (15%), protein degradation (8%), chromosome associated proteins (2%), ribosomal proteins (2%), and other function proteins (3%). Interestingly, 21 of the total host proteins have not been reported to be present in virions of other virus families, such as major vault protein, TENP protein, ovalbumin, and scavenger receptor protein. Following identification of the host proteins by proteomic methods, the presence of 4 proteins in the purified IBV preparation was verified by western blotting and immunogold labeling detection.ConclusionsThe results present the first standard proteomic profile of IBV and may facilitate the understanding of the pathogenic mechanisms.

Ovocalyxin-36 and other LBP/BPI/PLUNC-like proteins as molecular actors of the mechanisms of the avian egg natural defences

“…Little is known about TENP. It is notable that this protein was recently identified in a proteomic analysis of host proteins associated with purified coronavirus infectious bronchitis virus particles [44]. Both phylogeny and genomic comparison suggest that the chicken TENP gene is orthologous to the mammalian BPIL1 ( Figure 2).…”

Looking for a needle in a haystack: Cellular proteins that may interact with the tyrosine-based sorting signal of the TGEV S protein

“…Additionally, actin may be involved in the movement of viral proteins to the coronavirus assembly site. Actin was found to be incorporated into IB virions as well as into other coronavirus particles (Kong et al, 2010;Neuman et al, 2008;Nogales et al, 2012). Actin-binding proteins like tropomyosin were found to be enriched after IBV infection (Cao et al, 2011(Cao et al, , 2012.…”

“…In a proteomic analysis of an avian coronavirus, in purified infectious bronchitis virus (IBV) particles Kong and coworkers detected about 60 host proteins in addition to the viral proteins S and N (Kong et al, 2010). Kong et al used IBV strain H52 grown on 10-day-old SPF embryonated chicken eggs.…”

“…A MALDI-TOF/TOF analysis revealed the presence of the two viral proteins N and S and about 60 host proteins. Among them, 21 host proteins detected in purified IBV particles have not been described to be present in other virions (Kong et al, 2010). The reason for this may be that the virus was grown on embryonated eggs rather than in cultured cells, and that the amniotic fluid was used for virion purification.…”

“…This may be due to the use of amniotic fluid for virion purification. Another group of host proteins, the heat-shock proteins (HSPs) were found by both groups (Kong et al, 2010;Neuman et al, 2008). HSPs are multifunctional proteins that facilitate protein folding and unfolding, prevent protein aggregation, are involved in cell signaling, and participate in vesicular transport processes.…”