[Type IV collagenases (MMP-2 and MMP-9) and their substrates--intracellular proteins, hormones, cytokines, chemokines and their receptors].

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that cleave protein components of extracellular matrix such as collagens, laminin, fibronectin, proteoglycans and contribute to cell migration by eliminating the surrounding extracellular matrix and basement membrane barriers. However, the extracellular matrix is not simply an extracellular scaffold because, for example, it contains sites that can bind growth factors; therefore, degradation of the extracellular matrix components by MMPs can alter cellular behavior. MMPs also cleave a variety of non-ECM proteins, including cytokines, chemokines, and growth factors, activating or inactivating them, or generating other products that have biological consequences. The immune system is also influenced by MMPs. For that reason, the function of MMPs is much more complex and subtle than simple demolition. MMPs are essential for embryonic development and morphogenesis, however, exuberant expression of these enzymes has been associated with a variety of destructive diseases, including tumor progression, cardiovascular diseases and autoimmune diseases.