title: A novel metalloproteinase virulence factor is involved in Bacillus thuringiensis pathogenesis in nematodes and insects.
abstract: The Gram-positive soil bacterium Bacillus thuringiensis has been developed as the leading microbial insecticide for years. The pathogenesis of B. thuringiensis requires common extracellular factors that depend on the PlcR regulon, which regulates a large number of virulence factors; however, the precise role of many of these proteins is not known. In this study, we describe the complete lifecycle of a nematicidal B. thuringiensis strain in the free living nematode Caenorhabditis elegans using in vitro and in vivo molecular techniques to follow host and bacterial effectors during the infection process. We then focus on the metalloproteinase ColB, a collagenase, which was found highly important for destruction of the intestine thereby facilitates the adaptation and colonization of B. thuringiensis in C. elegans. In vivo green fluorescent protein (GFP) reporter-gene studies showed that ColB expression is highly induced and regulated by the global activator PlcR. Finally, we demonstrated that ColB also takes part in B. thuringiensis virulence in an insect model following injection and oral infection. Indeed, addition of purified ColB accelerates the action of Cry toxin proteins in insects, too. These results give novel insights into host adaptation for B. thuringiensis and other B. cereus group bacteria and highlight the role of collagenase metalloproteases to synergize infection process.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Donghai
authors.initials: D
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Jinshui
authors.initials: J
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Sun
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics / Q000472:pathogenicity*; D001426:Bacterial Proteins / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000382:microbiology*; D017364:Collagenases / Q000378:metabolism; D007313:Insecta / Q000382:microbiology*; D045726:Metalloproteases / Q000502:physiology*; D018085:Regulon; D014774:Virulence; D037521:Virulence Factors / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; D045726:Metalloproteases; D017364:Collagenases