The role of Bombyx mori Bmtutl-519 protein in the infection of BmN cells by Nosema bombycis. (March 2019)

• Record Type: Journal Article
• Authors: Zhu, Feng; Tang, Xudong; Xiao, Shengyan; Wang, Hongliang; Zhang, Yonghong; Shao, Yulan; Tang, Fenfen; Chen, Shiliang; Bai, Xingrong
• Is Part Of: Developmental and comparative immunology. Volume 92(2019)
• Page Start: 283
• Page End: 290
• Publication Date: 2019-03
• Subjects: Silkworm -- Nosema bombycis -- Bmtutl-519 -- NbSWP26 -- Heparin-binding motif (HBM); Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2018.12.003
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Bmtutl-519 is an isoform of the Bombyx Turtle protein and a member of the immunoglobulin superfamily (IgSF). The relative expression level of Bmtutl-519 was significantly upregulated when BmN cells were infected by Nosema bombycis . The subcellular localization of Bmtutl-519 was studied using an indirect immunoinfluscent assay (IFA), Co-localization assay, Western blotting, and enhanced green fluorescent protein (EGFP) fusion constructs expressed in BmN cells transfected with a Bmtutl-519 expression plasmid. The results indicate that Bmtutl-519 is distributed in both the cytoplasm and the cell membrane of BmN cells. Bmtutl-519 may be involved in the infection process of N. bombycis as a cell surface receptor or regulatory factor. Interaction analysis of Bmtutl-519 with NbSWP26, a spore wall protein of N. bombycis involved in host cell adherence and infection, showed that the C-terminal heparin-binding motif (HBM) of NbSWP26 mediates the interaction between these two proteins. Mutation of the NbSWP26 HBM at K208G, K209G, K210G, and K213G led to a loss of the ability to bind the Bmtutl-519 protein. Spore adherence and infection assays showed that Bmtutl-519 enhances the binding ability of N. bombycis to the host cell surface, but this did not enhance host cell infection by N. bombycis . In contrast, the sustained high expression of Bmtutl-519 in BmN cells inhibited the proliferation of N. bombycis spores. Graphical abstract: Highlights: Bmtutl-519 was distributed in both cytoplasm and cell membrane of BmN cells. The interaction between Bmtutl-519 and NbSWP26 was mediated by the C-terminal heparin-binding motif (HBM) of NbSWP26. Bmtutl-519 may serve as a receptor to N. bombycis spores through recognition of NbSWP26. Bmtutl-519 enhances the binding ability of N. bombycis to BmN cell, but the overexpression of Bmtutl-519 inhibited the proliferation of spores.