Cytochrome c maturation proteins are critical for in vivo growth of Legionella pneumophila.
Legionella pneumophila, an intracellular parasite of macrophages and protozoa, requires iron for extra- and intracellular growth. In a new screen of a mutant library of L. pneumophila for strains defective for growth on agar media lacking supplemental iron, seven mutants were obtained. All of the mutants had a disruption in the cytochrome c maturation (ccm) locus; two had insertions in ccmB, two in ccmC, and three in ccmF. The ccm mutants were unable to multiply within macrophage-like cells (i.e., U937 and THP-1 cells) and Hartmannella vermiformis amoebae. A competition assay in A/J mice revealed that ccm mutants are severely defective for growth within the lung. Taken together, these data confirm that ccm and cytochrome c maturation proteins are required for L. pneumophila growth in low iron, intracellular infection, and virulence.
Naylor
Jennifer
J
Department of Microbiology and Immunology, Northwestern University Medical School, 320 East Superior St., Chicago, IL 60611, USA.
Cianciotto
Nicholas P
NP
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D015169:Colony Count, Microbial; D005260:Female; D006249:Hartmannella / Q000382:microbiology*; D006801:Humans; D007501:Iron / Q000378:metabolism; D016952:Legionella pneumophila / Q000235:genetics / Q000254:growth & development*; D007877:Legionnaires' Disease / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009154:Mutation; D020298:U937 Cells
D001426:Bacterial Proteins; C116246:CcmC protein, bacteria; D008565:Membrane Proteins; D007501:Iron