title: Leptospiral outer membrane protein LipL41 is not essential for acute leptospirosis but requires a small chaperone protein, lep, for stable expression.
abstract: Leptospirosis is a worldwide zoonosis caused by pathogenic Leptospira spp., but knowledge of leptospiral pathogenesis remains limited. However, the development of mutagenesis systems has allowed the investigation of putative virulence factors and their involvement in leptospirosis. LipL41 is the third most abundant lipoprotein found in the outer membranes of pathogenic leptospires and has been considered a putative virulence factor. LipL41 is encoded on the large chromosome 28 bp upstream of a small open reading frame encoding a hypothetical protein of unknown function. This gene was named lep, for LipL41 expression partner. In this study, lipL41 was found to be cotranscribed with lep. Two transposon mutants were characterized: a lipL41 mutant and a lep mutant. In the lep mutant, LipL41 protein levels were reduced by approximately 90%. Lep was shown through cross-linking and coexpression experiments to bind to LipL41. Lep is proposed to be a molecular chaperone essential for the stable expression of LipL41. The roles of LipL41 and Lep in the pathogenesis of Leptospira interrogans were investigated; surprisingly, neither of these two unique proteins was essential for acute leptospirosis.
authors.affiliation: Department of Microbiology, Monash University, Clayton, Victoria, Australia.
authors.forename: Amy M
authors.initials: AM
authors.lastname: King
authors.forename: Thanatchaporn
authors.initials: T
authors.lastname: Bartpho
authors.forename: Rasana W
authors.initials: RW
authors.lastname: Sermswan
authors.forename: Dieter M
authors.initials: DM
authors.lastname: Bulach
authors.forename: Azad
authors.initials: A
authors.lastname: Eshghi
authors.forename: Mathieu
authors.initials: M
authors.lastname: Picardeau
authors.forename: Ben
authors.initials: B
authors.lastname: Adler
authors.forename: Gerald L
authors.initials: GL
authors.lastname: Murray
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015153:Blotting, Western; D006224:Cricetinae; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005798:Genes, Bacterial / Q000235:genetics; D007921:Leptospira interrogans / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D007922:Leptospirosis / Q000235:genetics* / Q000276:immunology; D008297:Male; D008647:Mesocricetus; D018832:Molecular Chaperones / Q000378:metabolism; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; C538745:LipL41 protein, Leptospira interrogans; D018832:Molecular Chaperones