title: 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.
authors: Department of Pediatrics, 462 Heritage Medical Research Center, University of Alberta, Edmonton, AB T6G 2S2, Canada.
authors: Meltem
authors: M
authors: Sariahmetoglu
authors: Bryan D
authors: BD
authors: Crawford
authors: Hernando
authors: H
authors: Leon
authors: Jolanta
authors: J
authors: Sawicka
authors: Laiji
authors: L
authors: Li
authors: Barbara J
authors: BJ
authors: Ballermann
authors: Charles
authors: C
authors: Holmes
authors: Luc G
authors: LG
authors: Berthiaume
authors: Andrew
authors: A
authors: Holt
authors: Grzegorz
authors: G
authors: Sawicki
authors: Richard
authors: R
authors: Schulz
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001665:Binding Sites; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D005354:Fibrosarcoma; D006706:Homeostasis; D006801:Humans; D013058:Mass Spectrometry; D020778:Matrix Metalloproteinase 2 / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism
chemical_list: D009363:Neoplasm Proteins; D010446:Peptide Fragments; D011493:Protein Kinase C; D000469:Alkaline Phosphatase; D014357:Trypsin; D020778:Matrix Metalloproteinase 2