Characterization of the interaction between outer-fiber protein VP55 of genotype III grass carp reovirus and Fibulin-4 of grass carp. Issue 86 (March 2019)

• Record Type: Journal Article
• Authors: Wang, Longlong; Yu, Fei; Sun, Hao; Lu, Liqun
• Is Part Of: Fish & shellfish immunology. Issue 86(2019)
• Page Start: 355
• Page End: 360
• Publication Date: 2019-03
• Subjects: Grass carp reovirus -- Fibulin-4 -- Outer-fiber protein -- Virus-host interaction; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2018.11.067
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Genotype III grass carp reovirus (GCRV; representative strain, GCRV-104) belongs to the subfamily Spinareovirinae and encodes an outer-fiber protein, VP55, responsible for mediating the infection of target tissues by the virus and assisting the virus into cells. Fibulin-4/EFEMP2 protein was previously identified as a putative binding partner for VP55 in a yeast two-hybrid screening. Here, we have further characterized the association between Fibulin-4 and VP55 by using protein interaction assays. An intracellular co-localization assay showed that RFP-Fibulin-4 co-localized with GFP-VP55 in grass carp ovary (GCO) cells. Bacterially expressed GST-tagged Fibulin-4 was shown to associate with baculovirus-expressed His-tagged VP55 in a dot-blot overlay assay; moreover, baculovirus-expressed His-tagged VP55 was able to pull down GFP-Fibulin-4 expressed in the GCO cells. We performed real-time PCR and immunoblotting analysis and showed that endogenous Fibulin-4, although suppressed to a lower level in the late infection phase, is present throughout the infection course of GCRV-104 in CIK cells. In conclusion, our results indicate that grass carp Fibulin-4 interacts with VP55. The presence of Fibulin-4, a well-known secreted protein, during the infection course of GCRV-104 in grass carp cells implies its potential role during viral egression through interaction with VP55. Highlights: VP55 of GCRV-104 physically interacts with fibulin-4. VP55 co-localizes with fibulin-4 in GCO cells. Fibulin-4 expression is suppressed but not abolished by GCRV-104. Fibulin-4 is potentially involved in viral attachment and egression.