101
|
Abstract
Pathogens develop creative ways to undermine host defenses. In this issue of Cell Host & Microbe, Bakowski et al. (2010) have unveiled a mechanism by which Salmonella evades lysosomal fusion by using a bacterial protein, SopB, that depletes the phagosomal membrane of negative charge.
Collapse
Affiliation(s)
- Bethany A Weigele
- Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8816, USA
| | | |
Collapse
|
102
|
Bakowski MA, Braun V, Lam GY, Yeung T, Heo WD, Meyer T, Finlay BB, Grinstein S, Brumell JH. The phosphoinositide phosphatase SopB manipulates membrane surface charge and trafficking of the Salmonella-containing vacuole. Cell Host Microbe 2010; 7:453-62. [PMID: 20542249 DOI: 10.1016/j.chom.2010.05.011] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 03/23/2010] [Accepted: 04/26/2010] [Indexed: 11/17/2022]
Abstract
Shifts in electrostatic surface charge of membranes have recently been highlighted as a significant factor contributing to protein targeting to the plasma membrane and nascent phagosomes. Intracellular, vacuole-adapted pathogens may also regulate surface charge of their vacuoles to establish a replicative niche. Since Salmonella enterica serovar Typhimurium controls trafficking of the Salmonella-containing vacuole (SCV) and inhibits its fusion with lysosomes, we investigated the contribution of surface charge to this process. Using recently developed fluorescent biosensors, we show that the bacterial phosphoinositide phosphatase SopB controls membrane surface charge of nascent SCVs by reducing levels of negatively charged lipids phosphatidylinositol-4,5-bisphosphate and phosphatidylserine. This SopB activity results in dissociation of a number of host-cell endocytic trafficking proteins from this compartment and inhibits SCV-lysosome fusion. Moreover, inducible reduction of negative charge rescues DeltasopB bacteria-containing SCVs from fusion with lysosomes. These results reveal a membrane-charge-based mechanism used by S. Typhimurium to control SCV maturation.
Collapse
Affiliation(s)
- Malina A Bakowski
- Cell Biology Program, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
103
|
Cossart P, Roy CR. Manipulation of host membrane machinery by bacterial pathogens. Curr Opin Cell Biol 2010; 22:547-54. [PMID: 20542678 DOI: 10.1016/j.ceb.2010.05.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 05/04/2010] [Accepted: 05/11/2010] [Indexed: 12/12/2022]
Abstract
Subversion of host membrane machinery is important for the uptake, survival, and replication of bacterial pathogens. Understanding how pathogens manipulate host membrane transport pathways provides mechanistic insight into how infection occurs and is also revealing new information on biochemical processes involved in the functioning of eukaryotic cells. In this review we discuss several of the canonical host pathways targeted by bacterial pathogens and emerging areas of investigation in this exciting field.
Collapse
Affiliation(s)
- Pascale Cossart
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, F-75015 Paris, France.
| | | |
Collapse
|
104
|
Braun V, Wong A, Landekic M, Hong WJ, Grinstein S, Brumell JH. Sorting nexin 3 (SNX3) is a component of a tubular endosomal network induced by Salmonella and involved in maturation of the Salmonella-containing vacuole. Cell Microbiol 2010; 12:1352-67. [PMID: 20482551 DOI: 10.1111/j.1462-5822.2010.01476.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Salmonella enterica serovar Typhimurium is an intracellular pathogen that grows within a modified endomembrane compartment, the Salmonella-containing vacuole (SCV). Maturation of nascent SCVs involves the recruitment of early endosome markers and the remodelling of phosphoinositides at the membrane of the vacuole, in particular the production of phosphatidylinositol 3-phosphate [PI(3)P]. Sorting nexins (SNXs) are a family of proteins characterized by the presence of a phox homology (PX) domain that binds to phosphoinositides and are involved in intracellular trafficking in eukaryotic cells. We therefore studied whether sorting nexins, particularly sorting nexin 3 (SNX3), play a role in Salmonella infection. We found that SNX3 transiently localized to SCVs at early times post invasion (10 min) and presented a striking tubulation phenotype in the vicinity of SCVs at later times (30-60 min). The bacterial effector SopB, which is known to promote PI(3)P production on SCVs, was required for the formation of SNX3 tubules. In addition, RAB5 was also required for the formation of SNX3 tubules. Depletion of SNX3 by siRNA impaired RAB7 and LAMP1 recruitment to the SCV. Moreover, the formation of Salmonella-induced filaments (Sifs) was altered by SNX3 knock-down. Therefore, SNX3 plays a significant role in regulating the maturation of SCVs.
Collapse
Affiliation(s)
- Virginie Braun
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada M5G1X8
| | | | | | | | | | | |
Collapse
|
105
|
Huang B, Hubber A, McDonough JA, Roy CR, Scidmore MA, Carlyon JA. The Anaplasma phagocytophilum-occupied vacuole selectively recruits Rab-GTPases that are predominantly associated with recycling endosomes. Cell Microbiol 2010; 12:1292-307. [PMID: 20345488 DOI: 10.1111/j.1462-5822.2010.01468.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Anaplasma phagocytophilum is an obligate intracellular bacterium that infects neutrophils to reside within a host cell-derived vacuole. The A. phagocytophilum-occupied vacuole (ApV) fails to mature along the endocytic pathway and is non-fusogenic with lysosomes. Rab GTPases regulate membrane traffic. To better understand how the bacterium modulates the ApV's selective fusogencity, we examined the intracellular localization of 20 green fluorescent protein (GFP) or red fluorescent protein (RFP)-tagged Rab GTPases in A. phagocytophilum-infected HL-60 cells. GFP-Rab4A, GFP-Rab10, GFP-Rab11A, GFP-Rab14, RFP-Rab22A and GFP-Rab35, which regulate endocytic recycling, and GFP-Rab1, which mediates endoplasmic reticulum to Golgi apparatus trafficking, localize to the ApV. Fluorescently tagged Rabs are recruited to the ApV upon its formation and remain associated throughout infection. Endogenous Rab14 localizes to the ApV. Tetracycline treatment concomitantly promotes loss of recycling endosome-associated GFP-Rabs and acquisition of GFP-Rab5, GFP-Rab7, and the lysosomal marker, LAMP-1. Wild-type and GTPase- deficient versions, but not GDP-restricted versions of GFP-Rab1, GFP-Rab4A and GFP-Rab11A, localize to the ApV. Strikingly, GFP-Rab10 recruitment to the ApV is guanine nucleotide-independent. These data establish that A. phagocytophilum selectively recruits Rab GTPases that are primarily associated with recycling endosomes to facilitate its intracellular survival and implicate bacterial proteins in regulating Rab10 membrane cycling on the ApV.
Collapse
Affiliation(s)
- Bernice Huang
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | | | | | | | | | | |
Collapse
|
106
|
Cardoso CMP, Jordao L, Vieira OV. Rab10 Regulates Phagosome Maturation and Its Overexpression RescuesMycobacterium-Containing Phagosomes Maturation. Traffic 2010; 11:221-35. [DOI: 10.1111/j.1600-0854.2009.01013.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
107
|
Modulation of membrane traffic between endoplasmic reticulum, ERGIC and Golgi to generate compartments for the replication of bacteria and viruses. Semin Cell Dev Biol 2009; 20:828-33. [PMID: 19508853 PMCID: PMC7110581 DOI: 10.1016/j.semcdb.2009.03.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 03/23/2009] [Accepted: 03/23/2009] [Indexed: 12/04/2022]
Abstract
Several bacteria and viruses remodel cellular membranes to form compartments specialised for replication. Bacteria replicate within inclusions which recruit membrane vesicles from the secretory pathway to provide nutrients for microbial growth and division. Viruses generate densely packed membrane vesicles called viroplasm which provide a platform to recruit host and viral proteins necessary for replication. This review describes examples where both intracellular bacteria (Salmonella, Chlamydia and Legionella) and viruses (picornaviruses and hepatitis C) recruit membrane vesicles to sites of replication by modulating proteins that control the secretory pathway. In many cases this involves modulation of Rab and Arf GTPases.
Collapse
|
108
|
The GTPase Rab3b/3c-positive recycling vesicles are involved in cross-presentation in dendritic cells. Proc Natl Acad Sci U S A 2009; 106:15801-6. [PMID: 19717423 DOI: 10.1073/pnas.0905684106] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Antigen cross-presentation in dendritic cells is a complex intracellular membrane transport process, but the underlying molecular mechanisms remain to be thoroughly investigated. In this study, we examined the effect of siRNA-mediated knockdown of 57 Rab GTPases, the key regulators of membrane trafficking, on antigen cross-presentation. Twelve Rab GTPases were identified to be associated with antigen cross-presentation, and Rab3b/3c was indicated to be colocalized with MHC class I molecules at perinuclear tubular structure. Tracing with fluorescence protein-tagged beta(2)-microglobulin demonstrated that the MHC class I molecules were internalized from the plasma membrane to Rab3b/3c-positive compartments, which were also colocalized with the internalized transferrin. Moreover, depletion of Rab3b/3c strongly reduced the fast phase recycling rate of transferrin receptors. Furthermore, the Rab3b/3c-positive compartments were colocalized with a fraction of Rab27a at a juxtaposition of phagosomes. Together, these data demonstrate that Rab3b/3c-positive recycling vesicles are involved in and may constitute one of the recycling compartments in exogenous antigen cross-presentation.
Collapse
|
109
|
Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 and 5410=5410-- pmza] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
110
|
|
111
|
|
112
|
|
113
|
|
114
|
|
115
|
|
116
|
|
117
|
|
118
|
|
119
|
|
120
|
|
121
|
|
122
|
|
123
|
Stenmark H. Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 and 6285=8708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
124
|
Stenmark H. Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 order by 1-- gjxv] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
125
|
|
126
|
|
127
|
|
128
|
|
129
|
|
130
|
|
131
|
|
132
|
|
133
|
Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 order by 1#] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
134
|
|
135
|
|
136
|
|
137
|
|
138
|
|
139
|
|
140
|
|
141
|
|
142
|
|
143
|
|
144
|
|
145
|
|
146
|
Stenmark H. Rab GTPases as coordinators of vesicle traffic. Nat Rev Mol Cell Biol 2009. [DOI: 10.1038/nrm2728 and 5410=5410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
147
|
|
148
|
|
149
|
|
150
|
|