TY - JOUR
T1 - The Legionella IcmS-IcmW protein complex is important for Dot/Icm-mediated protein translocation
AU - Ninio, Shira
AU - Zuckman-Cholon, Deborah M.
AU - Cambronne, Eric D.
AU - Roy, Craig R.
PY - 2005/2
Y1 - 2005/2
N2 - The intracellular pathogen Legionella pneumophila can infect and replicate within macrophages of a human host. To establish infection, Legionella require the Dot/Icm secretion system to inject protein substrates directly into the host cell cytoplasm. The mechanism by which substrate proteins are engaged and translocated by the Dot/Icm system is not well understood. Here we show that two cytosolic components of the Dot/Icm secretion machinery, the proteins IcmS and EcmW, play an important role in substrate translocation. Biochemical analysis indicates that IcmS and IcmW form a stable protein complex. In Legionella, the IcmW protein is rapidly degraded in the absence of the IcmS protein. Substrate proteins translocated into mammalian host cells by the Dot/Icm system were identified using the IcmW protein as bait in a yeast two-hybrid screen. It was determined that the IcmS-IcmW complex interacts with these substrates and plays an important role in translocation of these proteins into mammalian cells. These data are consistent with the IcmS-IcmW complex being involved in the recognition and Dot/ Icm-dependent translocation of substrate proteins during Legionella infection of host cells.
AB - The intracellular pathogen Legionella pneumophila can infect and replicate within macrophages of a human host. To establish infection, Legionella require the Dot/Icm secretion system to inject protein substrates directly into the host cell cytoplasm. The mechanism by which substrate proteins are engaged and translocated by the Dot/Icm system is not well understood. Here we show that two cytosolic components of the Dot/Icm secretion machinery, the proteins IcmS and EcmW, play an important role in substrate translocation. Biochemical analysis indicates that IcmS and IcmW form a stable protein complex. In Legionella, the IcmW protein is rapidly degraded in the absence of the IcmS protein. Substrate proteins translocated into mammalian host cells by the Dot/Icm system were identified using the IcmW protein as bait in a yeast two-hybrid screen. It was determined that the IcmS-IcmW complex interacts with these substrates and plays an important role in translocation of these proteins into mammalian cells. These data are consistent with the IcmS-IcmW complex being involved in the recognition and Dot/ Icm-dependent translocation of substrate proteins during Legionella infection of host cells.
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U2 - 10.1111/j.1365-2958.2004.04435.x
DO - 10.1111/j.1365-2958.2004.04435.x
M3 - Article
C2 - 15661013
AN - SCOPUS:13444262298
SN - 0950-382X
VL - 55
SP - 912
EP - 926
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 3
ER -