Sylke Pioch

Publications of Sylke Pioch

• Nitric Oxide-Independent Vasodilator Rescues Heme-Oxidized Soluble Guanylate Cyclase From Proteasomal Degradation.

  Authors: Sabine Meurer, Sylke Pioch, Tatjana Pabst, Nils Opitz, Peter M Schmidt, Tobias Beckhaus, Kristina Wagner, Simone Matt, Kristina Gegenbauer, Sandra Geschka, Michael Karas, Johannes-Peter Stasch, Harald H H W Schmidt, Werner Müller-Esterl

  Circulation research. 06/2009;

  Nitric oxide (NO) is an essential vasodilator. In vascular diseases, oxidative stress attenuates NO signaling by both chemical scavenging of free NO and oxidation and downregulation of its majorNitric oxide (NO) is an essential vasodilator. In vascular diseases, oxidative stress attenuates NO signaling by both chemical scavenging of free NO and oxidation and downregulation of its major intracellular receptor, the alphabeta heterodimeric heme-containing soluble guanylate cyclase (sGC). Oxidation can also induce loss of the heme of sGC, as well as the responsiveness of sGC to NO. sGC activators such as BAY 58-2667 bind to oxidized/heme-free sGC and reactivate the enzyme to exert disease-specific vasodilation. Here, we show that oxidation-induced downregulation of sGC protein extends to isolated blood vessels. Mechanistically, degradation was triggered through sGC ubiquitination and proteasomal degradation. The heme-binding site ligand BAY 58-2667 prevented sGC ubiquitination and stabilized both alpha and beta subunits. Collectively, our data establish oxidation-ubiquitination of sGC as a modulator of NO/cGMP signaling and point to a new mechanism of action for sGC activating vasodilators by stabilizing their receptor, oxidized/heme-free sGC.

• Nitric oxide-independent vasodilator rescues heme-oxidized soluble guanylate cyclase from proteosomal degradation

  Authors: Sabine Meurer, Sylke Pioch, Tatjana Pabst, Nils Opitz, Peter Schmidt, Tobias Beckhaus, Kristina Wagner, Simone Matt, Kristina Gegenbauer, Sandra Geschka, Michael Karas, Johannes-Peter Stasch, Harald Schmidt, Werner Müller-Esterl

  BMC Pharmacology. 01/2009;

• Oxidative stress induces CHIP-mediated ubiquitination and roteasomal degradation of soluble guanylyl cyclase

  Authors: Sabine Meurer, Tatjana Pabst, Sylke Pioch, Nils Opitz, Peter Schmidt, Kristina Wagner, Simone Matt, Harald Schmidt, Werner Müller-Esterl

  BMC Pharmacology. 01/2007;

• Reactive oxygen species induce tyrosine phosphorylation of and Src kinase recruitment to NO-sensitive guanylyl cyclase.

  Authors: Sabine Meurer, Sylke Pioch, Steffen Gross, Werner Müller-Esterl

  The Journal of biological chemistry. 10/2005; 280(39):33149-56.

  Soluble guanylyl cyclase (sGC) is the major cytosolic receptor for nitric oxide (NO) that converts GTP into the second messenger cGMP in a NO-dependent manner. Other factors controlling this keySoluble guanylyl cyclase (sGC) is the major cytosolic receptor for nitric oxide (NO) that converts GTP into the second messenger cGMP in a NO-dependent manner. Other factors controlling this key enzyme are intracellular proteins such as Hsp90 and PSD95, which bind to sGC and modulate its activity, stability, and localization. To date little is known about the effects of posttranslational modifications of sGC, although circumstantial evidence suggests that reversible phosphorylation may contribute to sGC regulation. Here we demonstrate that inhibitors of protein-tyrosine phosphatases such as pervanadate and bisperoxo(1,10-phenanthroline)oxovanadate(V) as well as reactive oxygen species such as H2O2 induce specific tyrosine phosphorylation of the beta1 but not of the alpha1 subunit of sGC. Tyrosine phosphorylation of sGCbeta1 is also inducible by pervanadate and H2O2 in intact PC12 cells, rat aortic smooth muscle cells, and in rat aortic tissues, indicating that tyrosine phosphorylation of sGC may also occur in vivo. We have mapped the major tyrosine phosphorylation site to position 192 of beta1, where it forms part of a highly acidic phospho-acceptor site for Src-like kinases. In the phosphorylated state Tyr(P)-192 exposes a docking site for SH2 domains and efficiently recruits Src and Fyn to sGCbeta1, thereby promoting multiple phosphorylation of the enzyme. Our results demonstrate that sGC is subject to tyrosine phosphorylation and interaction with Src-like kinases, revealing an unexpected cross-talk between the NO/cGMP and tyrosine kinase signaling pathways at the level of sGC.

• Tyrosine phosphorylation of NO-sensitive guanylyl cyclase

  Authors: Sabine Meurer, Steffen Gross, Sylke Pioch, Werner Müller-Esterl

  BMC Pharmacology. 01/2005;

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

  Authors: Sylke Pioch, Sabine Meurer, Steffen Gross, Werner Müller-Esterl

  BMC Pharmacology. 01/2005;

• Reactive oxygen species induce tyrosine phosphorylation of and Src kinase recruitment to NO-sensitive guanylyl cyclase

  Authors: Sabine Meurer, Steffen Gross, Sylke Pioch, Werner Müller-Esterl

  BMC Pharmacology. 01/2005;

• AGAP1, a novel binding partner of nitric oxide-sensitive guanylyl cyclase.

  Authors: Sabine Meurer, Sylke Pioch, Kristina Wagner, Werner Müller-Esterl, Steffen Gross

  The Journal of biological chemistry. 12/2004; 279(47):49346-54.

  Nitric oxide (NO)-sensitive soluble guanylyl cyclase (sGC) is the major cytosolic receptor for NO, catalyzing the conversion of GTP to cGMP. In a search for proteins specifically interacting withNitric oxide (NO)-sensitive soluble guanylyl cyclase (sGC) is the major cytosolic receptor for NO, catalyzing the conversion of GTP to cGMP. In a search for proteins specifically interacting with human sGC, we have identified the multidomain protein AGAP1, the prototype of an ArfGAP protein with a GTPase-like domain, Ankyrin repeats, and a pleckstrin homology domain. AGAP1 binds through its carboxyl terminal portion to both the alpha1 and beta1 subunits of sGC. We demonstrate that AGAP1 mRNA and protein are co-expressed with sGC in human, murine, and rat cells and tissues and that the two proteins interact in vitro and in vivo. We also show that AGAP1 is prone to tyrosine phosphorylation by Src-like kinases and that tyrosine phosphorylation potently increases the interaction between AGAP1 and sGC, indicating that complex formation is modulated by reversible phosphorylation. Our findings may hint to a potential role of AGAP1 in integrating signals from Arf, NO/cGMP, and tyrosine kinase signaling pathways.