title: Interaction and assembly of two novel proteins in the spore wall of the microsporidian species Nosema bombycis and their roles in adherence to and infection of host cells.
abstract: Microsporidia are obligate intracellular parasites with rigid spore walls that protect against various environmental pressures. Despite an extensive description of the spore wall, little is known regarding the mechanism by which it is deposited or the role it plays in cell adhesion and infection. In this study, we report the identification and characterization of two novel spore wall proteins, SWP7 and SWP9, in the microsporidian species Nosema bombycis. SWP7 and SWP9 are mainly localized to the exospore and endospore of mature spores and the cytoplasm of sporonts, respectively. In addition, a portion of SWP9 is targeted to the spore wall of sporoblasts earlier than SWP7 is. Both SWP7 and SWP9 are specifically colocalized to the spore wall in mature spores. Furthermore, immunoprecipitation, far-Western blotting, unreduced SDS-PAGE, and yeast two-hybrid data demonstrated that SWP7 interacted with SWP9. The chitin binding assay showed that, within the total spore protein, SWP9 and SWP7 can bind to the deproteinated chitin spore coats (DCSCs) of N. bombycis. However, binding of the recombinant protein rSWP7-His to the DCSCs is dependent on the combination of rSWP9-glutathione S-transferase (GST) with the DCSCs. Finally, rSWP9-GST, anti-SWP9, and anti-SWP7 antibodies decreased spore adhesion and infection of the host cell. In conclusion, SWP7 and SWP9 may have important structural capacities and play significant roles in modulating host cell adherence and infection in vitro. A possible major function of SWP9 is as a scaffolding protein that supports other proteins (such as SWP7) that form the integrated spore wall of N. bombycis.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, Shanxi, People's Republic of China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Donglin
authors.initials: D
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China College of Life Sciences, Chongqing Normal University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Xiaoqun
authors.initials: X
authors.lastname: Dang
authors.affiliation: Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, Shanxi, People's Republic of China.
authors.forename: Yawei
authors.initials: Y
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Pai
authors.initials: P
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China Chongqing Three Gorges Medical College, Chongqing, China.
authors.forename: Maofei
authors.initials: M
authors.lastname: Bian
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China College of Life Sciences, Chongqing Normal University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Zhengang
authors.initials: Z
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China Chongqing Tobacco Science Research Institute, Southwest University, Chongqing, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Geng
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China College of Life Sciences, Chongqing Normal University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China.
authors.forename: Cuifang
authors.initials: C
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China College of Life Sciences, Chongqing Normal University, Chongqing, China Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China zyzhou@swu.edu.cn.
authors.forename: Zeyang
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000382:microbiology*; D002448:Cell Adhesion / Q000502:physiology*; D002460:Cell Line; D002473:Cell Wall / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D054884:Host-Pathogen Interactions / Q000276:immunology*; D008969:Molecular Sequence Data; D016818:Nosema / Q000378:metabolism / Q000472:pathogenicity*; D011485:Protein Binding; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000378:metabolism / Q000472:pathogenicity*
chemical_list: D005656:Fungal Proteins