Dataset Information

Quantitative analysis of the exoproteome from a Staphylococcus aureus LAC sarA mutant

ABSTRACT: The staphylococcal accessory regulator A (sarA) impacts the extracellular accumulation of Staphylococcus aureus virulence factors at the level of intracellular production and extracellular protease-mediated degradation. To assess the relative impact of these two functions, we previously used a proteomics approach that measures protein abundance as a function of all proteoforms to demonstrate that mutation of sarA results in increased levels of extracellular proteases and assess the impact of this on the accumulation of S. aureus exoproteins1. While this approach confirmed that protease-mediated degradation has a significant impact on the S. aureus exoproteome, it was potentially limited in that it did not take into account the possibility that large, stable proteolytic products from a given protein could result in false negatives when quantified by total proteoforms. Here, we present an expanded proteomics approach that utilizes a dual quantitative method for measuring abundance at both the total proteoform and full-length exoprotein levels. Specifically, proteins present in conditioned medium from overnight, stationary phase cultures of the USA300 strain LAC, an isogenic sarA mutant, and a sarA mutant unable to produce any of the known extracellular proteases (sarA/protease) were resolved using one-dimensional gel electrophoresis. Using methods that focus on total proteoforms vs. methods that focus specifically on full-length proteins, quantitative proteomic comparisons of sarA vs sarA/protease mutants identified proteins that were degraded in a protease dependent manner owing to mutation of sarA, while comparisons of a sarA/protease mutant vs the LAC parent strain identified proteins in which abundance was altered in a sarA mutant in a protease-independent manner. Furthermore, the proteins uniquely identified by the full-length data analysis approach eliminated false negatives observed in the total proteoform analysis. This approach provided for a more comprehensive and robust analysis of the impact of mutating sarA and protease-mediated degradation on the S. aureus exoproteome.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Staphylococcus Aureus

TISSUE(S): Cell Culture

DISEASE(S): Osteomyelitis

SUBMITTER: Stephanie Byrum

LAB HEAD: Alan J. Tackett

PROVIDER: PXD009614 | Pride | 2018-11-21

REPOSITORIES: Pride

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Dataset's files

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			Action	DRS
	Smeltzer_092116_2279A_01.raw	Raw
	Smeltzer_092116_2279A_01.raw (F034766).mzid_Smeltzer_092116_2279A_01.raw_(F034766).pride.mgf.gz	Mzid
	Smeltzer_092116_2279A_01.raw (F034766).pride.mztab.gz	Mztab
	Smeltzer_092116_2279A_01.rawF034766.mzid.gz	Mzid
	Smeltzer_092116_2279A_01.rawF034766.mzid_Smeltzer_092116_2279A_01.raw_F034766.MGF	Mzid

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Publications

Label-Free Proteomic Approach to Characterize Protease-Dependent and -Independent Effects of sarA Inactivation on the Staphylococcus aureus Exoproteome.

Byrum Stephanie D SD Loughran Allister J AJ Beenken Karen E KE Orr Lisa M LM Storey Aaron J AJ Mackintosh Samuel G SG Edmondson Ricky D RD Tackett Alan J AJ Smeltzer Mark S MS

Journal of proteome research 20180927 10

The staphylococcal accessory regulator A ( sarA) impacts the extracellular accumulation of Staphylococcus aureus virulence factors at the level of intracellular production and extracellular protease-mediated degradation. We previously used a proteomics approach that measures protein abundance of all proteoforms to demonstrate that mutation of sarA results in increased levels of extracellular proteases and assesses the impact of this on the accumulation of S. aureus exoproteins. Our previous appr ...[more]

PMID: 30209945

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