You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Legionella pneumophila Inhibits Macrophage Apoptosis by Targeting Pro-Death Members of the Bcl2 Protein Family
Simran Banga, Ping Gao, Xihui Shen, Valena Fiscus, Wei-Xing Zong, Lingling Chen and Zhao-Qing Luo
Proceedings of the National Academy of Sciences of the United States of America
Vol. 104, No. 12 (Mar. 20, 2007), pp. 5121-5126
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/25427154
Page Count: 6
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
To establish a vacuole that supports bacterial replication, Legionella pneumophila translocates a large number of bacterial proteins into host cells via the Dot/Icm type IV secretion system. Functions of most of these translocated proteins are unknown, but recent investigations suggest their roles in modulating diverse host processes such as vesicle trafficking, autophagy, ubiquitination, and apoptosis. Cells infected by L. pneumophila exhibited resistance to apoptotic stimuli, but the bacterial protein directly involved in this process remained elusive. We show here that SidF, one substrate of the Dot/Icm transporter, is involved in the inhibition of infected cells from undergoing apoptosis to allow maximal bacterial multiplication. Permissive macrophages harboring a replicating sidF mutant are more apoptotic and more sensitive to staurosporine-induced cell death. Furthermore, cells expressing SidF are resistant to apoptosis stimuli. SidF contributes to apoptosis resistance in L. pneumophila-infected cells by specifically interacting with and neutralizing the effects of BNIP3 and Bcl-rambo, two proapoptotic members of Bcl2 protein family. Thus, inhibiting the functions of host pro-death proteins by translocated effectors constitutes a mechanism for L. pneumophila to protect host cells from apoptosis.
Proceedings of the National Academy of Sciences of the United States of America © 2007 National Academy of Sciences