Possible link between a 35 kDa membrane protein and osmolyte transport in Staphylococcus aureus

ABSTRACTStaphylococcus aureusis responsible for a significant amount of devastating disease. Its ability to colonize the host and cause infection is supported by a variety of proteins that are dependent on the cofactor heme. Heme is a porphyrin used broadly across kingdoms and is synthesizedde novofrom common cellular precursors and iron. While heme is critical to bacterial physiology, it is also toxic in high concentrations, requiring that organisms encode regulatory processes to control heme homeostasis. In this work, we describe a posttranscriptional regulatory strategy inS. aureusheme biosynthesis. The first committed enzyme in theS. aureusheme biosynthetic pathway, glutamyl-tRNA reductase (GtrR), is regulated by heme abundance and the integral membrane protein HemX. GtrR abundance increases dramatically in response to heme deficiency, suggesting a mechanism by whichS. aureusresponds to the need to increase heme synthesis. Additionally, HemX is required to maintain low levels of GtrR in heme-proficient cells, and inactivation ofhemXleads to increased heme synthesis. Excess heme synthesis in a ΔhemXmutant activates the staphylococcal heme stress response, suggesting that regulation of heme synthesis is critical to reduce self-imposed heme toxicity. Analysis of diverse organisms indicates that HemX is widely conserved among heme-synthesizing bacteria, suggesting that HemX is a common factor involved in the regulation of GtrR abundance. Together, this work demonstrates thatS. aureusregulates heme synthesis by modulating GtrR abundance in response to heme deficiency and through the activity of the broadly conserved HemX.IMPORTANCEStaphylococcus aureusis a leading cause of skin and soft tissue infections, endocarditis, bacteremia, and osteomyelitis, making it a critical health care concern. Development of new antimicrobials againstS. aureusrequires knowledge of the physiology that supports this organism’s pathogenesis. One component of staphylococcal physiology that contributes to growth and virulence is heme. Heme is a widely utilized cofactor that enables diverse chemical reactions across many enzyme families.S. aureusrelies on many critical heme-dependent proteins and is sensitive to excess heme toxicity, suggestingS. aureusmust maintain proper intracellular heme homeostasis. BecauseS. aureusprovides heme for heme-dependent enzymes via synthesis from common precursors, we hypothesized that regulation of heme synthesis is one mechanism to maintain heme homeostasis. In this study, we identify thatS. aureusposttranscriptionally regulates heme synthesis by restraining abundance of the first heme biosynthetic enzyme, GtrR, via heme and the broadly conserved membrane protein HemX.

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WIPI-1 Positive Autophagosome-Like Vesicles Entrap PathogenicStaphylococcus aureusfor Lysosomal Degradation

International Journal of Cell Biology ◽

10.1155/2012/179207 ◽

2012 ◽

Vol 2012 ◽

pp. 1-13 ◽

Cited By ~ 22

Author(s):

Mario Mauthe ◽

Wenqi Yu ◽

Oleg Krut ◽

Martin Krönke ◽

Friedrich Götz ◽

...

Keyword(s):

Electron Microscopy ◽

Staphylococcus Aureus ◽

Cell Division ◽

Membrane Protein ◽

Host Cell ◽

Effector Function ◽

Host Cells ◽

Lysosomal Degradation ◽

Content Analyses ◽

Confocal And Electron Microscopy

Invading pathogens provoke the autophagic machinery and, in a process termed xenophagy, the host cell survives because autophagy is employed as a safeguard for pathogens that escaped phagosomes. However, some pathogens can manipulate the autophagic pathway and replicate within the niche of generated autophagosome-like vesicles. By automated fluorescence-based high content analyses, we demonstrate thatStaphylococcus aureusstrains (USA300, HG001, SA113) stimulate autophagy and become entrapped in intracellular PtdIns(3)P-enriched vesicles that are decorated with human WIPI-1, an essential PtdIns(3)P effector of canonical autophagy and membrane protein of both phagophores and autophagosomes. Further,agr-positiveS. aureus(USA300, HG001) strains were more efficiently entrapped in WIPI-1 positive autophagosome-like vesicles when compared toagr-negative cells (SA113). By confocal and electron microscopy we provide evidence that single- and multiple-Staphylococci entrapped undergo cell division. Moreover, the number of WIPI-1 positive autophagosome-like vesicles entrapping Staphylococci significantly increased upon (i) lysosomal inhibition by bafilomycin A1and (ii) blocking PIKfyve-mediated PtdIns(3,5)P2generation by YM201636. In summary, our results provide evidence that the PtdIns(3)P effector function of WIPI-1 is utilized during xenophagy ofStaphylococcus aureus. We suggest that invadingS. aureuscells become entrapped in autophagosome-like WIPI-1 positive vesicles targeted for lysosomal degradation in nonprofessional host cells.

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Teicoplanin-resistant Staphylococcus aureus expresses a novel membrane protein and increases expression of penicillin-binding protein 2 complex.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.37.11.2432 ◽

1993 ◽

Vol 37 (11) ◽

pp. 2432-2437 ◽

Cited By ~ 55

Author(s):

D M Shlaes ◽

J H Shlaes ◽

S Vincent ◽

L Etter ◽

P D Fey ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Membrane Protein ◽

Binding Protein ◽

Penicillin Binding Protein

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A human endothelial cell membrane protein that binds Staphylococcus aureus in vitro.

Journal of Clinical Investigation ◽

10.1172/jci114560 ◽

1990 ◽

Vol 85 (4) ◽

pp. 1248-1254 ◽

Cited By ~ 27

Author(s):

D C Tompkins ◽

V B Hatcher ◽

D Patel ◽

G A Orr ◽

L L Higgins ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Endothelial Cell ◽

Cell Membrane ◽

Membrane Protein ◽

Human Endothelial Cell ◽

Cell Membrane Protein

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A small membrane protein critical to both the offensive and defensive capabilities of Staphylococcus aureus

10.1101/712737 ◽

2019 ◽

Author(s):

Seána Duggan ◽

Maisem Laabei ◽

Alaa Alnahari ◽

Eóin C. O’Brien ◽

Keenan A. Lacey ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Immune System ◽

Membrane Protein ◽

Iron Homeostasis ◽

Treatment Strategies ◽

Population Level ◽

Toxin Production ◽

Effective Control ◽

Significant Impairment ◽

The Stability

AbstractStaphylococcus aureus is a major human pathogen, where the widespread emergence of antibiotic resistance is making infections more challenging to treat. Toxin induced tissue damage and resistance to the host’s immune system are well established as critical to its ability to cause disease. However, recent attempts to study S. aureus pathogenicity at a population level have revealed significant complexity and hierarchical levels of regulation. In an effort to better understand this we have identified and characterized a principle effector protein, MasA. The inactivation of this small highly-conserved membrane protein simultaneously disrupts toxin production and impairs S. aureus’ ability to resist several aspects of the innate immune system. These pleiotropic effects are mediated by both a change in the stability of the bacterial membrane and the dysregulation of iron homeostasis, which results in a significant impairment in the ability of S. aureus to cause infection in both a subcutaneous and a sepsis model of infection. That proteins with such major effects on pathogenicity remain unidentified in a bacterium as well studied as S. aureus demonstrates how incomplete our understanding of their ability to cause disease is, an issue that needs to be addressed if effective control and treatment strategies are to be developed.

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Isolation of a Membrane Protein Complex for Type VII Secretion in Staphylococcus aureus

Journal of Bacteriology ◽

10.1128/jb.00482-17 ◽

2017 ◽

Vol 199 (23) ◽

Cited By ~ 13

Author(s):

Khaled A. Aly ◽

Mark Anderson ◽

Ryan Jay Ohr ◽

Dominique Missiakas

Keyword(s):

Staphylococcus Aureus ◽

Membrane Protein ◽

Bacterial Species ◽

Dominant Negative ◽

Central Component ◽

Machine Component ◽

Secretion Systems ◽

Content Type ◽

Type Vii Secretion ◽

Mobile Machine

ABSTRACT The ESAT6-like secretion system (ESS) of Staphylococcus aureus promotes effector protein transport across the bacterial envelope. Genes in the ESS cluster are required for S. aureus establishment of persistent abscess lesions and the modulation of immune responses during bloodstream infections. However, the biochemical functions of most of the ESS gene products, specifically the identity of secretion machine components, are unknown. Earlier work demonstrated that deletion of essB, which encodes a membrane protein, abolishes S. aureus ESS secretion. Loss-of-function mutations truncating the essB gene product cause dominant-negative phenotypes on ESS secretion, suggesting that EssB is a central component of the secretion machinery. To test this prediction, we purified native and affinity-tagged EssB from staphylococcal membranes via dodecyl-maltoside extraction, identifying a complex assembled from five proteins, EsaA, EssA, EssB, EssD, and EsxA. All five proteins are essential for secretion, as knockout mutations in the corresponding genes abolish ESS transport. Biochemical and bacterial two-hybrid analyses revealed a direct interaction between EssB and EsaA that, by engaging a mobile machine component, EsxA, may also recruit EssA and EssD. IMPORTANCE Type VII secretion systems support the lifestyle of Gram-positive bacteria, including important human pathogens such as Bacillus anthracis, Mycobacterium tuberculosis, and Staphylococcus aureus. Genes encoding SpoIIIE-FtsK-like ATPases and WXG100-secreted products are conserved features of type VII secretion pathways; however, most of the genes in T7SS clusters are not conserved between different bacterial species. Here, we isolate a complex of proteins from the membranes of S. aureus that appears to represent the core secretion machinery, designated ESS. These results suggest that three membrane proteins, EsaA, EssB, and EssA, form a secretion complex that associates with EssC, the SpoIIIE-FtsK-like ATPase, and with EsxA, a mobile machine component and member of the WXG100 protein family.

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New immunochemical method for rapid detection of human choriogonadotropin in urine.

Clinical Chemistry ◽

10.1093/clinchem/33.6.800 ◽

1987 ◽

Vol 33 (6) ◽

pp. 800-802

Author(s):

Z Shoham ◽

E Katz ◽

I Blickstein ◽

Z Katz ◽

A Zosmer ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Membrane Protein ◽

Concanavalin A ◽

Human Urine ◽

Rapid Detection ◽

Immunochemical Method ◽

Human Choriogonadotropin ◽

Test Kit ◽

Antigen Complex ◽

Visual Assay

Abstract We describe a visual assay for rapid detection of choriogonadotropin (hGC) in human urine, and evaluate a pregnancy test kit that is based on this assay and designed for use by the general public. The assay involves the formation of an antibody-antigen complex between the anti-hGC antibodies coated on the membrane protein of Staphylococcus aureus bacteria, prestained with hematoxylin, and the hGC concentrated on a column of Sepharose-concanavalin A. The test was calibrated to detect as little hGC as 0.9 (SD 0.15) int. unit/mL. The kit, clinically tested with 448 urine samples, was 99.6% accurate. Simple to perform, the test gives highly reliable results as early as five days after the missed menstrual period.

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