Identification of the second membrane-type matrix metalloproteinase (MT-MMP-2) gene from a human placenta cDNA library. MT-MMPs form a unique membrane-type subclass in the MMP family.
Membrane-type matrix metalloproteinase (MT-MMP), which we have identified recently, is unique in its transmembrane (TM) domain at the C terminus and mediates activation of pro-gelatinase A on the cell surface (Sato, H., Takino, T., Okada, Y., Cao, J., Shinagawa, A., Yamamoto, E., and Seiki, M. (1994) Nature 370, 61-65; Takino, T., Sato, H., Yamamoto, E., and Seiki, M. (1995) Gene (Amst.) 115, 293-298). In addition to MT-MMP, a novel MMP-related cDNA of 2.1 kilobases was isolated from a human placenta cDNA library. The cDNA contains an open reading frame for a new MMP. The deduced protein composed of 604 amino acids was closely related to MT-MMP in the amino acid sequence (66% homology at the catalytic domains) and has a potential TM domain at the C terminus. Monoclonal antibodies raised against the synthetic peptide recognized a 64-kDa protein as the major product in the transfected cells. TIMP-1 fused with the potential TM domain was localized on the cell surface while native TIMP-1 is in the culture medium. Thus, we called the second membrane-type MMP, MT-MMP-2 and renamed MT-MMP, MT-MMP-1. MT-MMP-1 and -2 are thought to form a distinct membrane-type subclass in the MMP family since all the others are secreted as soluble forms. Like MT-MMP-1, expression of MT-MMP-2 induced processing of pro-gelatinase A (68-kDa in gelatin zymography) into the activated form of 62-kDa fragments through a 64-kDa intermediate form. Expression of MT-MMP-2 mRNA was at the highest levels in the brain where MT-MMP-1 was at the lowest level compared to other tissues. MT-MMP-1 and -2 are thought to be utilized for extracellular matrix turnover on the surface of cells under different genetic controls.
Takino
T
T
Department of Molecular Virology and Oncology, Kanazawa University, Ishikawa, Japan.
Sato
H
H
Shinagawa
A
A
Seiki
M
M
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D002522:Chlorocebus aethiops; D018076:DNA, Complementary; D000939:Epitopes / Q000276:immunology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D018093:Gelatinases / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D015723:Gene Library; D006801:Humans; D020778:Matrix Metalloproteinase 2; D008666:Metalloendopeptidases / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D051379:Mice / Q000276:immunology; D008969:Molecular Sequence Data; D005810:Multigene Family; D016254:Mutagenesis, Insertional; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D000939:Epitopes; D011994:Recombinant Proteins; D018093:Gelatinases; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2