Matrix metalloproteinase-9 (IPR028688)

Short name: MMP9

Overlapping homologous superfamilies


Family relationships


Matrix metalloproteinases (MMPs) are zinc-dependent and calcium-dependent proteases that cleave within a polypeptide (endopeptidases). They degrade most components of the extracellular matrix (such as growth factors, their binding proteins, and other bioactive molecules, as well as binding sites for cell-surface molecules) and some non-extracellular-matrix molecules [PMID: 12801404]. Two categories of MMPs can be recognised based on their cellular localisation: soluble vs. membrane-bound. The soluble MMPs are divided into the collagenases (MMP1, MMP8 and MMP13), gelatinases (MMP2 and MMP9), stromelysins (MMP3, MMP12) and those yet to be classified. The membrane-bound MMPs include MT1, 2, 3, 4, 5 and their hallmark is the presence of plasma membrane anchoring domains [PMID: 12027585]. MMPs are highly expressed in various cancers, both by tumour cells and in surrounding stromal cells such as macrophages [PMID: 12801404].

This entry represents matrix metalloproteinase-9 (MMP9, also known as gelatinase B), which is involved in matrix remodelling during the normal processes of embryogenesis, tissue remodelling and development [PMID: 22326910]. It is released extracellularly in a pro-form with the enzymatic site covered by a propeptide that has to be cleaved off to reveal the activity. MMP9 can cleave gelatin types I and V and collagen types IV and V [PMID: 1480034]. It plays an essential role in local proteolysis of the extracellular matrix and in leukocyte migration [PMID: 17709402, PMID: 22496659]. MMP9 is one of the key regulators for remodelling skeletal tissues [PMID: 12814943], and could play a role in bone osteoclastic resorption triggered by inflammatory processes [PMID: 22410640, PMID: 15883642]. MMP9 also has a role in synaptic plasticity [PMID: 22326910]. MMP9 cleaves the metastasis suppressor gene product KiSS1 [PMID: 12879005].

GO terms

Biological Process

GO:0030574 collagen catabolic process
GO:0050900 leukocyte migration
GO:0001503 ossification
GO:0006508 proteolysis

Molecular Function

GO:0004222 metalloendopeptidase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.