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Mycobacterium tuberculosis tyrosine phosphatase A (PtpA) activity is modulated by S-nitrosylation

Gabriela Ecco1, Javier Vernal, Guilherme Razzera

  • 1Centro de Biologia Molecular Estrutural, BQA CCB UFSC, Florianópolis-SC, Brazil.

Chemical Communications (Cambridge, England)
|September 11, 2010
PubMed

Insights

Mycobacterium tuberculosis phosphotyrosine phosphatases PtpA and PtpB are crucial for survival. Researchers found that PtpA, but not PtpB, is susceptible to S-nitrosylation at Cys53, a modification by nitric oxide.

Area of Science:

  • Microbiology
  • Biochemistry
  • Molecular Biology

Background:

  • Mycobacterium tuberculosis possesses two phosphotyrosine phosphatases, PtpA and PtpB.
  • These enzymes are vital for the survival of mycobacteria within host macrophages.
  • Nitric oxide (NO) is a key signaling molecule involved in host defense mechanisms.

Purpose of the Study:

  • To investigate the susceptibility of M. tuberculosis PtpA and PtpB to S-nitrosylation.
  • To identify specific cysteine residues targeted by S-nitrosylation in these phosphatases.

Main Methods:

  • Site-directed mutagenesis was employed to identify target cysteine residues.
  • The study focused on the interaction between nitric oxide and the target proteins.

Main Results:

  • PtpB was found to be resistant to modification by nitric oxide.
  • PtpA was identified as being susceptible to S-nitrosylation.
  • Specifically, Cys53 of PtpA was determined to be the site of S-nitrosylation.

Conclusions:

  • M. tuberculosis PtpA is a target of S-nitrosylation at Cys53.
  • This modification by nitric oxide may play a role in the regulation of PtpA activity or function during macrophage infection.
  • PtpB is not affected by S-nitrosylation under the conditions tested.

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