Bim and Bmf synergize to induce apoptosis in Neisseria gonorrhoeae infection.
Bcl-2 family proteins including the pro-apoptotic BH3-only proteins are central regulators of apoptotic cell death. Here we show by a focused siRNA miniscreen that the synergistic action of the BH3-only proteins Bim and Bmf is required for apoptosis induced by infection with Neisseria gonorrhoeae (Ngo). While Bim and Bmf were associated with the cytoskeleton of healthy cells, they both were released upon Ngo infection. Loss of Bim and Bmf from the cytoskeleton fraction required the activation of Jun-N-terminal kinase-1 (JNK-1), which in turn depended on Rac-1. Depletion and inhibition of Rac-1, JNK-1, Bim, or Bmf prevented the activation of Bak and Bax and the subsequent activation of caspases. Apoptosis could be reconstituted in Bim-depleted and Bmf-depleted cells by additional silencing of antiapoptotic Mcl-1 and Bcl-X(L), respectively. Our data indicate a synergistic role for both cytoskeletal-associated BH3-only proteins, Bim, and Bmf, in an apoptotic pathway leading to the clearance of Ngo-infected cells.
Kepp
Oliver
O
Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany.
Gottschalk
Kathleen
K
Churin
Yuri
Y
Rajalingam
Krishnaraj
K
Brinkmann
Volker
V
Machuy
Nikolaus
N
Kroemer
Guido
G
Rudel
Thomas
T
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D000072224:Bcl-2-Like Protein 11; D015153:Blotting, Western; D002448:Cell Adhesion / Q000502:physiology; D003599:Cytoskeleton / Q000648:ultrastructure; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006069:Gonorrhea / Q000378:metabolism* / Q000473:pathology; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D048055:Mitogen-Activated Protein Kinase 8 / Q000378:metabolism; D009344:Neisseria gonorrhoeae / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D034741:RNA, Small Interfering; D015398:Signal Transduction / Q000502:physiology*; D020744:rac GTP-Binding Proteins / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; C000606775:BCL2L11 protein, human; C486655:BMF protein, human; D000072224:Bcl-2-Like Protein 11; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D048055:Mitogen-Activated Protein Kinase 8; D020744:rac GTP-Binding Proteins