Show simple item record

dc.contributor.authorKnodler, Leigh A
dc.contributor.authorWinfree, Seth
dc.contributor.authorDrecktrah, Dan
dc.contributor.authorIreland, Robin
dc.contributor.authorSteele-Mortimer, Olivia
dc.date.accessioned2010-03-12T15:35:50Z
dc.date.available2010-03-12T15:35:50Z
dc.date.issued2009-11
dc.identifier.citationUbiquitination of the bacterial inositol phosphatase, SopB, regulates its biological activity at the plasma membrane. 2009, 11 (11):1652-70 Cell. Microbiol.en
dc.identifier.issn1462-5822
dc.identifier.pmid19614667
dc.identifier.doi10.1111/j.1462-5822.2009.01356.x
dc.identifier.urihttp://hdl.handle.net/10147/94199
dc.description.abstractThe Salmonella type III effector, SopB, is an inositol polyphosphate phosphatase that modulates host cell phospholipids at the plasma membrane and the nascent Salmonella-containing vacuole (SCV). Translocated SopB persists for many hours after infection and is ubiquitinated but the significance of this covalent modification has not been investigated. Here we identify by mass spectrometry six lysine residues of SopB that are mono-ubiquitinated. Substitution of these six lysine residues with arginine, SopB-K(6)R, almost completely eliminated SopB ubiquitination. We found that ubiquitination does not affect SopB stability or membrane association, or SopB-dependent events in SCV biogenesis. However, two spatially and temporally distinct events are dependent on ubiquitination, downregulation of SopB activity at the plasma membrane and prolonged retention of SopB on the SCV. Activation of the mammalian pro-survival kinase Akt/PKB, a downstream target of SopB, was intensified and prolonged after infection with the SopB-K(6)R mutant. At later times, fewer SCV were decorated with SopB-K(6)R compared with SopB. Instead SopB-K(6)R was present as discrete vesicles spread diffusely throughout the cell. Altogether, our data show that ubiquitination of SopB is not related to its intracellular stability but rather regulates its enzymatic activity at the plasma membrane and intracellular localization.
dc.language.isoenen
dc.subject.meshAmino Acid Substitution
dc.subject.meshBacterial Proteins
dc.subject.meshCell Membrane
dc.subject.meshHela Cells
dc.subject.meshHumans
dc.subject.meshLysine
dc.subject.meshMutagenesis, Site-Directed
dc.subject.meshProtein Stability
dc.subject.meshSalmonella
dc.subject.meshUbiquitination
dc.subject.meshVirulence Factors
dc.titleUbiquitination of the bacterial inositol phosphatase, SopB, regulates its biological activity at the plasma membrane.en
dc.contributor.departmentLaboratory of Intracellular Parasites, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA. lknodler@niaid.nih.goven
dc.identifier.journalCellular microbiologyen
refterms.dateFOA2018-09-03T10:38:18Z
html.description.abstractThe Salmonella type III effector, SopB, is an inositol polyphosphate phosphatase that modulates host cell phospholipids at the plasma membrane and the nascent Salmonella-containing vacuole (SCV). Translocated SopB persists for many hours after infection and is ubiquitinated but the significance of this covalent modification has not been investigated. Here we identify by mass spectrometry six lysine residues of SopB that are mono-ubiquitinated. Substitution of these six lysine residues with arginine, SopB-K(6)R, almost completely eliminated SopB ubiquitination. We found that ubiquitination does not affect SopB stability or membrane association, or SopB-dependent events in SCV biogenesis. However, two spatially and temporally distinct events are dependent on ubiquitination, downregulation of SopB activity at the plasma membrane and prolonged retention of SopB on the SCV. Activation of the mammalian pro-survival kinase Akt/PKB, a downstream target of SopB, was intensified and prolonged after infection with the SopB-K(6)R mutant. At later times, fewer SCV were decorated with SopB-K(6)R compared with SopB. Instead SopB-K(6)R was present as discrete vesicles spread diffusely throughout the cell. Altogether, our data show that ubiquitination of SopB is not related to its intracellular stability but rather regulates its enzymatic activity at the plasma membrane and intracellular localization.


Files in this item

Thumbnail
Name:
19614667.pdf
Size:
820.6Kb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record