Regulation of matrix metalloproteinase‐2 (MMP‐2) activity by phosphorylation

Abstract

The regulation of matrix metalloproteinases (MMP) has been studied extensively due to the fundamental roles these zinc-endopeptidases play in diverse physiological and pathological processes. However, phosphorylation has not previously been considered as a potential modulator of MMP activity. The ubiquitously expressed MMP-2 contains 29 potential phosphorylation sites. Mass spectrometry reveals that at least five of these sites are phosphorylated in hrMMP-2 expressed in mammalian cells. Treatment of HT1080 cells with an activator of protein kinase C results in a change in MMP-2 immunoreactivity on 2D immunoblots consistent with phosphorylation, and purified MMP-2 is phosphorylated by protein kinase C in vitro. Furthermore, MMP-2 from HT1080 cell-conditioned medium is immunoreactive with antibodies directed against phosphothreonine and phosphoserine, which suggests that it is phosphorylated. Analysis of MMP-2 activity by zymography, gelatin dequenching assays, and measurement of kinetic parameters shows that the phosphorylation status of MMP-2 significantly affects its enzymatic properties. Consistent with this, dephosphorylation of MMP-2 immunoprecipitated from HT1080 conditioned medium with alkaline phosphatase significantly increases its activity. We conclude that MMP-2 is modulated by phosphorylation on multiple sites and that protein kinase C may be a regulator of this protease in vivo.

Effects of cisplatin on matrix metalloproteinase-2 in transformed thyroid cells

“…The same results were obtained when PKC-δ was down regulated by siRNA (Fig 3.A and B). The data are consistent with other showing that MMP-2 is modulated by phosphorylation and that PKC may be, in vivo, a regulator of this protease [28], PKC-δ included [29]. Indeed, we found that in response to cisPt administration a subsequent PKC-δ activation occurred after as soon as 15 min (Fig 3.C).…”

Dimerization of Matrix Metalloproteinase-2 (MMP-2)

“…3A, right). Human MMP-2 contains 29 potential phosphorylation sites, and some of them are phosphorylated by PKC (31). Thus, we examined the phosphorylation status of MMP-2 in the conditioned medium of transfected COS-1 cells treated with or without PMA by Western blotting with antibodies against phosphothreonine and phosphoserine.…”

Metalloproteinases: key and common mediators of multiple GPCRs and candidate therapeutic targets in models of hypertensive cardiac disease

“…Metalloproteinase activation can result from oxidative stress [19,20], post-translational modifications such as phosphorylation [21] and protein-protein interactions [22,23].…”

“…Cardiac PKC may modulate intracellular MMP-2 activity by phosphorylation at multiple sites including Ser and Thr residues. Indeed, mammalian MMP-2 contains 29 potential phosphorylation sites and mass spectrometry reveals that at least five of these sites are phosphorylated [21]. The kinase activity of extracellular signal-regulated kinase, ERK, leads to phosphorylation of the Thr 735 of ADAM-17/TACE rendering ADAM-17 able to shed tumor necrosis factor (TNF)-α [29].…”