title: Intradomain cleavage of inhibitory prodomain is essential to protumorigenic function of membrane type-1 matrix metalloproteinase (MT1-MMP) in vivo.
abstract: Invasive cancers use pericellular proteolysis to breach the extracellular matrix and basement membrane barriers and invade the surrounding tissue. Proinvasive membrane type-1 matrix metalloproteinase (MT1-MMP) is the primary mediator of proteolytic events on the cancer cell surface. MT1-MMP is synthesized as a zymogen. The latency of MT1-MMP is maintained by its N-terminal inhibitory prodomain. In the course of MT1-MMP activation, the R(108)RKR(111) ↓ Y(112) prodomain sequence is processed by furin. The intact prodomain released by furin alone, however, is a potent inhibitor of the emerging MT1-MMP enzyme. Evidence suggests that the prodomain undergoes intradomain cleavage at the PGD ↓ L(50) site followed by the release of the degraded prodomain by furin cleavage that finalizes the two-step activation event. These cleavages, only if combined, cause the activation of MT1-MMP. The significance of the intradomain cleavage in the protumorigenic program of MT1-MMP, however, remained unidentified. To identify this important parameter, in our current study, we used the cells that expressed the wild-type prodomain-based fluorescent biosensor and the mutant biosensor with the inactivated PGD↓L(50) cleavage site (L50D mutant) and also the cells with the enforced expression of the wild-type and L50D mutant MT1-MMP. Using cell-based tests, orthotopic breast cancer xenografts in mice, and genome-wide transcriptional profiling of cultured cells and tumor xenografts, we demonstrated that the intradomain cleavage of the PGD ↓ L(50) sequence of the prodomain is essential for the protumorigenic function of MT1-MMP. Our results emphasize the importance of the intradomain cleavages resulting in the inactivation of the respective inhibitory prodomains not only for MT1-MMP but also for other MMP family members.
authors.affiliation: Cancer Research Center, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA.
authors.forename: Vladislav S
authors.initials: VS
authors.lastname: Golubkov
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Chernov
authors.forename: Alex Y
authors.initials: AY
authors.lastname: Strongin
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics; D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000235:genetics; D005260:Female; D045683:Furin / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D020125:Mutation, Missense; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009368:Neoplasm Transplantation; D014183:Transplantation, Heterologous
chemical_list: D009363:Neoplasm Proteins; C468731:FURIN protein, human; D045683:Furin; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14