title: Mlp24 (McpX) of Vibrio cholerae implicated in pathogenicity functions as a chemoreceptor for multiple amino acids.
abstract: The chemotaxis of Vibrio cholerae, the causative agent of cholera, has been implicated in pathogenicity. The bacterium has more than 40 genes for methyl-accepting chemotaxis protein (MCP)-like proteins (MLPs). In this study, we found that glycine and at least 18 L-amino acids, including serine, arginine, asparagine, and proline, serve as attractants to the classical biotype strain O395N1. Based on the sequence comparison with Vibrio parahaemolyticus, we speculated that at least 17 MLPs of V. cholerae may mediate chemotactic responses. Among them, Mlp24 (previously named McpX) is required for the production of cholera toxin upon mouse infection. mlp24 deletion strains of both classical and El Tor biotypes showed defects in taxis toward several amino acids, which were complemented by the expression of Mlp24. These amino acids enhanced methylation of Mlp24. Serine, arginine, asparagine, and proline were shown to bind directly to the periplasmic fragment of Mlp24. The structural information of its closest homolog, Mlp37, predicts that Mlp24 has two potential ligand-binding pockets per subunit, the membrane distal of which was suggested, by mutational analyses, to be involved in sensing of amino acids. These results suggest that Mlp24 is a chemoreceptor for multiple amino acids, including serine, arginine, and asparagine, which were previously shown to stimulate the expression of several virulence factors, implying that taxis toward a set of amino acids plays critical roles in pathogenicity of V. cholerae.
authors: Department of Frontier Bioscience, Faculty of Bioscience and Applied Chemistry, Hosei University, Tokyo, Japan.
authors: So-ichiro
authors: S
authors: Nishiyama
authors: Daisuke
authors: D
authors: Suzuki
authors: Yasuaki
authors: Y
authors: Itoh
authors: Kazuho
authors: K
authors: Suzuki
authors: Hirotaka
authors: H
authors: Tajima
authors: Akihiro
authors: A
authors: Hyakutake
authors: Michio
authors: M
authors: Homma
authors: Susan M
authors: SM
authors: Butler-Wu
authors: Andrew
authors: A
authors: Camilli
authors: Ikuro
authors: I
authors: Kawagishi
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002633:Chemotaxis; D017353:Gene Deletion; D005816:Genetic Complementation Test; D051379:Mice; D008958:Models, Molecular; D011487:Protein Conformation; D014734:Vibrio cholerae / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D014736:Vibrio parahaemolyticus / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D037521:Virulence Factors