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  • Poster presentation
  • Open Access

Interaction of NO-sensitive guanylyl cyclase with Src-like kinases

  • 1Email author,
  • 1,
  • 1 and
  • 1
BMC Pharmacology20055 (Suppl 1) :P43

https://doi.org/10.1186/1471-2210-5-S1-P43

  • Published:

Keywords

  • Tyrosine Phosphorylation
  • COS1 Cell
  • Guanylyl Cyclase
  • Immunofluorescence Study
  • Sequence Segment

NO-sensitive guanylyl cyclases (soluble guanylyl cyclase, sGC) are among the key regulators of intracellular cGMP concentration. The mechanisms underlying NO-mediated activation of sGC are quite well understood, however, little is known about the fine-tuning of sGC activity through alternative mechanisms such as protein phosphorylation. Several reports have demonstrated the reversible phosphorylation of sGC on serine/threonine residues, and it has been speculated, though not experimentally proven, that sGC might also be phosphorylated on tyrosine residues. Using broad-spectrum phosphatase inhibitors we were able to demonstrate tyrosine phosphorylation at Tyr192 of the β1 subunit of human sGC in COS1 cells. This residue forms part of a sequence segment (YEDL) representing a preferential binding site for SH2 domains of Src-like kinases. Pull-down assays and co-immunoprecipitation experiments showed that Src can indeed bind via its SH2 domain to pTyr192 of β1 indicating that tyrosine phosphorylation of sGC may be followed by recruitment of Src-like kinases to the phosphorylated β1 subunit. In support of this hypothesis, immunofluorescence studies showed a colocalization of overexpressed sGC and Src at the plasma membrane of COS1 and Hela cells. Together, our results point to an unexpected crosstalk between tyrosine kinase pathway(s) and the NO/cGMP signalling cascade which may result in translocation of the predominantly cytosolic sGC to the cytosolic face of the plasma membrane.

Authors’ Affiliations

(1)
Institute for Biochemistry II, University of Frankfurt Medical School, Frankfurt, Germany

Copyright

© BioMed Central Ltd 2005

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