Ubiquitination of the bacterial inositol phosphatase, SopB, regulates its biological activity at the plasma membrane.

Hdl Handle:
http://hdl.handle.net/10147/94199
Title:
Ubiquitination of the bacterial inositol phosphatase, SopB, regulates its biological activity at the plasma membrane.
Authors:
Knodler, Leigh A; Winfree, Seth; Drecktrah, Dan; Ireland, Robin; Steele-Mortimer, Olivia
Affiliation:
Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA. lknodler@niaid.nih.gov
Citation:
Ubiquitination of the bacterial inositol phosphatase, SopB, regulates its biological activity at the plasma membrane. 2009, 11 (11):1652-70 Cell. Microbiol.
Journal:
Cellular microbiology
Issue Date:
Nov-2009
URI:
http://hdl.handle.net/10147/94199
DOI:
10.1111/j.1462-5822.2009.01356.x
PubMed ID:
19614667
Abstract:
The 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.
Language:
en
MeSH:
Amino Acid Substitution; Bacterial Proteins; Cell Membrane; Hela Cells; Humans; Lysine; Mutagenesis, Site-Directed; Protein Stability; Salmonella; Ubiquitination; Virulence Factors
ISSN:
1462-5822

Full metadata record

DC FieldValue Language
dc.contributor.authorKnodler, Leigh Aen
dc.contributor.authorWinfree, Sethen
dc.contributor.authorDrecktrah, Danen
dc.contributor.authorIreland, Robinen
dc.contributor.authorSteele-Mortimer, Oliviaen
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

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