NEW INSIGHTS ON MOLECULES IN A GLANCE



MATRIX METALLOPROTEINASES

Matrix metalloproteinases (MMP) also called matrixin belong to the family of metalloendopeptidases. This family includes matrixin, thermolysin, astacin, serratia and snake venom metalloproteinases. Within the matrixin family, at least three distinct subsets of enzymes which include collagenases, gelatinases and stromelysins with at least nine protein members have been recognized (table I). These enzymes possess the ability to degrade extracellular matrix components including collagens, gelatins, fibronectin, laminin and proteoglcan.


Table I. The matrix metalloproteinase (matrixin) family
_______________________________________________________
Group        MMP#       Other names assigned                   
_______________________________________________________
Collagenases
             MMP-1      Interstitial collagenase, CLG, CLGN                
                        EC 3.4.24.7                             

             MMP-8      PMN collagenase, CLG1                        
                        EC 3.4.24.34
Gelatinases
             MMP-2      Gelatinase A                          
                        72 kD gelatinase                       
                        Type IV collagenase
                        EC 3.4.24.24

             MMP-9      Gleatinase B                            
                        92 kD gelatinase                        
                        Type IV collagenase                     
                        EC 3.4.24.35

             MMP-7      Punctuated MP (PUMP)                                
                        Matrilysin                    
                        Uterine MP     
                        EC 3.4.24.23
Stromelysins
             MMP-3      Stromelysin-1                          
                        Transin (rat)                          
                        Procollagenase activator
                        EC 3.4.24.17

             MMP-10     Stromelysin-2                         
                        Transin-2 (rat)
                        EC 3.4.24.22

             MMP-11     Stromelysin-3                         
Others
             MMP-12     Metallo-elastase (mouse)
             MMP-13     COLLAGENASE 3; CLG3 
             MMP-14     MMP14, MEMBRANE-TYPE
_______________________________________________________
Adapted from S Tabibzadeh, The signals and molecular 
pathways involved in human mentruation, a unique process 
of tissue destruction and remodelling. Mol Hum Reprod 
2, 77-92, 1996
In the May 31, 96 issue of Cell, Brooks et al, described that one of the members of the metalloportease family, MMP-2, was expressed on the surface of the cancer cells including melanoma cells in vitro. They also demonstrated that this molecule bound to integrin v3. Both MMP-2 and v3 were found on the angiogenic blood vessels and melanoma cells in vivo. Presence of MMP-2 on the surface of tumor cells not only aids the degradation of extracellular matrix by the neoplastic cells, it facilitates their motility and directed cell invarion.

Miyazaki et al describe cloning of three cDNAs containing coding regions of new MMPs (2D-1, 2D-19, and 2D-24) from second day postamputation regenerating limbs, and a cDNA (EB-1) was cloned from early bud-stage regenerating limbs. The deduced amino acid sequences of 2D-1, 2D-19, 2D-24, and EB-1 had a homology with mammalian MMP9, MMP3/10, MMP3/10, and MMP13, respectively. The expression levels of the new MMPs were dramatically increased after amputation These findings suggest that MMPs play an important role(s) in tissue remodeling of the regenerating limbs.

Peter C. Brooks, Staffan Strömblad, Luraynne C. Sanders, Tami L. von Schalscha, Ronald T. Aimes, William G. Stetler­Stevenson, James P. Quigley, and David A. Cheresh: Localization of Matrix Metalloproteinase MMP-2 to the Surface of Invasive Cells by Interaction with Integrin v3. Cell 1996

Koyomi Miyazaki, Kohji Uchiyama, Yutaka Imokawa, Katsutoshi Yoshizato: Cloning and characterization of cDNAs for matrix metalloproteinases of regenerating newt limbs. Proc Natl Acad Sci USA 93, 6819-6824, 1996

HOMEPAGEQUICKFINDER