Matrix metalloproteinases (MMPs) play key roles in tissue remodelling under normal development and, especially, in diseases ranging from malignancies to stroke. We cloned and thoroughly characterized the novel human and mouse MMP gene encoding MMP-21. MMP-21 is the last uncharacterized MMP coded by the human genome. Human and mouse MMP-21 is the orthologue of Xenopus laevis X-MMP. The latent proenzyme of MMP-21 (569 amino acid residues) consists of the prodomain, the catalytic domain and the haemopexin-like domain, and is potentially capable of being activated in its secretory pathway to the extracellular milieu by furin-like proprotein convertases. Human MMP-21 is the probable target gene of the Wnt pathway. In addition, the expression of MMP-21 is controlled uniquely by Pax and Notch transcription factors known to be critical for organogenesis. MMP-21 is expressed transiently in mouse embryogenesis and increased in embryonic neuronal tissues. Our observations clearly indicate that there is an important specific function for MMP-21 in embryogenesis, especially in neuronal cells.
- extracellular matrix
- glial tissue
- human genome
- matrix metalloproteinase-21
- neuronal tissue
Abbreviations used: APMA, 4-aminophenylmercuric acetate; EMSA, electrophoretic mobility-shift assay; GSK, glycogen synthase kinase; HRP, horseradish peroxidase; LEF-1, lymphoid enhancer factor-1; MMP, matrix metalloproteinase; MT, membrane type; RACE, rapid amplification of cDNA ends; RBP-Jκ, repressor-binding protein Jκ; Tcf, T-cell factor.
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