Article

Platelet-derived growth factor (PDGF) regulates Slingshot phosphatase activity via Nox1-dependent auto-dephosphorylation of serine 834 in vascular smooth muscle cells.

Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia 30322, USA.
Journal of Biological Chemistry (impact factor: 4.77). 08/2011; 286(41):35430-7. DOI:10.1074/jbc.M111.268284 pp.35430-7
Source: PubMed

ABSTRACT Migration of vascular smooth muscle cells (VSMCs) contributes to vascular pathology. PDGF induces VSMC migration by a Nox1-based NADPH oxidase mediated mechanism. We have previously shown that PDGF-induced migration in VSMCs requires Slingshot-1L (SSH1L) phosphatase activity. In the present work, the mechanism of SSH1L activation by PDGF is further investigated. We identified a 14-3-3 consensus binding motif encompassing Ser-834 in SSH1L that is constitutively phosphorylated. PDGF induces SSH1L auto-dephosphorylation at Ser-834 in wild type (wt), but not in Nox1(-/y) cells. A SSH1L-S834A phospho-deficient mutant has significantly lower binding capacity for 14-3-3 when compared with the phospho-mimetic SSH1L-S834D mutant, and acts as a constitutively active phosphatase, lacking of PDGF-mediated regulation. Given that Nox1 produces reactive oxygen species, we evaluated their participation in this SSH1L activation mechanism. We found that H(2)O(2) activates SSH1L and this is accompanied by SSH1L/14-3-3 complex disruption and 14-3-3 oxidation in wt, but not in Nox1(-/y) cells. Together, these data demonstrate that PDGF activates SSH1L in VSMC by a mechanism that involves Nox1-mediated oxidation of 14-3-3 and Ser-834 SSH1L auto-dephosphorylation.

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Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

14-3-3 consensus binding motif encompassing Ser-834
 
constitutively active phosphatase
 
constitutively phosphorylated
 
involves Nox1-mediated oxidation
 
Nox1-based NADPH oxidase
 
PDGF activates SSH1L
 
PDGF induces SSH1L auto-dephosphorylation
 
PDGF induces VSMC migration
 
PDGF-induced migration
 
PDGF-mediated regulation
 
phospho-mimetic SSH1L-S834D mutant
 
reactive oxygen species
 
Ser-834 SSH1L auto-dephosphorylation
 
SSH1L activation
 
SSH1L activation mechanism
 
SSH1L-S834A phospho-deficient mutant
 
SSH1L/14-3-3 complex disruption
 
vascular pathology
 
vascular smooth muscle cells
 
wild type