Platelet-derived Growth Factor (PDGF) Regulates Slingshot Phosphatase Activity Via Nox1-dependent Auto-dephosphorylation of Serine 834 in Vascular Smooth Muscle Cells
Overview
Authors
Affiliations
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.
He H, Jiang T, Ding M, Zhu Y, Xu X, Huang Y Redox Biol. 2024; 79():103477.
PMID: 39721498 PMC: 11732235. DOI: 10.1016/j.redox.2024.103477.
Lamb F, Choi H, Miller M, Stark R Hypertension. 2024; 81(4):752-763.
PMID: 38174563 PMC: 10954410. DOI: 10.1161/HYPERTENSIONAHA.123.19434.
Nox1-based NADPH oxidase regulates the Par protein complex activity to control cell polarization.
Valdivia A, Duran C, Lee M, Williams H, Lee M, San Martin A Front Cell Dev Biol. 2023; 11:1231489.
PMID: 37635877 PMC: 10457011. DOI: 10.3389/fcell.2023.1231489.
Alqawlaq S, Livne-Bar I, Williams D, DErcole J, Leung S, Chan D J Biol Chem. 2020; 296:100118.
PMID: 33234594 PMC: 7948738. DOI: 10.1074/jbc.RA120.015389.
Franca K, Martinez P, Prado M, Lo S, Borges B, Zanata S Arch Biochem Biophys. 2019; 679:108220.
PMID: 31812669 PMC: 8011465. DOI: 10.1016/j.abb.2019.108220.