Overproduction of metalloproteinases by v-mos-transformed rat kidney (6m2) cells.
Using monoclonal antibodies, we previously detected two forms of transformation-associated proteins (TAPs), P64 and P68, in the rat kidney (6m2) cells transformed by the temperature-sensitive 110-murine sarcoma virus-Moloney-mutant. TAPs were secreted as glycoproteins by 6m2 cells grown at 33 degrees C, but not by 6m2 cells grown at 39 degrees C. The identity and functions of TAPs were previously unknown. By molecular cloning techniques and immunoscreening, we have isolated two different cDNA clones (34A and 79B3) that were found by Western blot analysis to code for an anti-TAP monoclonal antibody-reactive polypeptide of approximately 58,000 daltons. The nucleotide sequence of 34A cDNA was determined and found to be identical to that of rat transin-2. The deduced amino acid sequence of 34A shares 71% sequence identity with rat transin and 41% to 76% identity with three human metalloproteinases. Partial nucleotide sequencing data indicated that 79B3 may be the rat transin gene. When either 34A cDNA or 79B3-cDNA was used as a probe in Northern blot analysis, one mRNA band of approximately 1.9 kb was detected in 6m2 cells at the permissive temperature of 33 degrees C. Similar RNA was either not detected or detected at very low level in 6m2 cells grown at the non-permissive 39 degrees C. These results suggest that at the non-permissive 39 degrees C, these two genes were not transcribed at the same level as that at 33 degrees C. Zymogram further confirmed that P64 and P68 have metalloproteinase activities. Apparently, the two proteins which we formerly designated TAPs are members of the rat transin gene family. Therefore, within v-mos transformed 6m2 cells, the absence of TAPs (metalloproteinases) at the non-permissive temperature was due to the very poor transcription of the two rat transin genes. This article presents a review of the biochemical properties of TAPs and their eventual identification as rat transin-2 and transin.
Chan
J C
JC
Department of Tumor Biology, University of Texas, M.D. Anderson Cancer Center, Houston 77030-4009.
D000818:Animals; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D016258:Genes, mos; D019278:Matrix Metalloproteinase 3; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008980:Moloney murine sarcoma virus; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D012513:Sarcoma, Experimental / Q000378:metabolism*
D009363:Neoplasm Proteins; D008666:Metalloendopeptidases; D019278:Matrix Metalloproteinase 3