title: Mycobacterium avium subsp. paratuberculosis PtpA is an endogenous tyrosine phosphatase secreted during infection.
abstract: Adaptive gene expression in prokaryotes is mediated by protein kinases and phosphatases. These regulatory proteins mediate phosphorylation of histidine or aspartate in two-component systems and serine/threonine or tyrosine in eukaryotic and eukaryote-like protein kinase systems. The genome sequence of Mycobacterium avium subsp. paratuberculosis, the causative agent of Johne's disease, does not possess a defined tyrosine kinase. Nevertheless, it encodes for protein tyrosine phosphatases. Here, we report that Map1985, is a functional low-molecular tyrosine phosphatase that is secreted intracellularly upon macrophage infection. This finding suggests that Map1985 might contribute to the pathogenesis of Mycobacterium avium subsp. paratuberculosis by dephosphorylating essential macrophage signaling and/or adaptor molecules.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of British Columbia, 2733 Heather St., Vancouver, V5Z 3J5 British Columbia, Canada. hbach@interchange.ubc.ca
authors.forename: Horacio
authors.initials: H
authors.lastname: Bach
authors.forename: Jim
authors.initials: J
authors.lastname: Sun
authors.forename: Zakaria
authors.initials: Z
authors.lastname: Hmama
authors.forename: Yossef
authors.initials: Y
authors.lastname: Av-Gay
mesh_terms: D000190:Actinomyces / Q000201:enzymology; D000595:Amino Acid Sequence; D002478:Cells, Cultured; D017124:Conserved Sequence; D006801:Humans; D008264:Macrophages / Q000201:enzymology / Q000382:microbiology*; D008969:Molecular Sequence Data; D009162:Mycobacterium avium / Q000201:enzymology*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000201:enzymology*; D017027:Protein Tyrosine Phosphatases / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D011994:Recombinant Proteins; D017027:Protein Tyrosine Phosphatases