Open AccessCloning of a complementary dna for rabbit proactivator. a metalloproteinase that activates synovial cell collagenase, shares homology with stromelysin and transin, and is coordinately regulated with collagenase
Author(s) -
Fini M. Elizabeth,
Karmilowicz Michael J.,
Ruby Peggy L.,
Beeman Anne M.,
Borges Kimberly A.,
Brinckerhoff Constance E.
Publication year - 1987
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780301108
Subject(s) - microbiology and biotechnology , collagenase , complementary dna , messenger rna , metalloproteinase , activator (genetics) , biology , northern blot , plasminogen activator , matrix metalloproteinase , biochemistry , gene , enzyme , endocrinology
Rabbit proactivator is a neutral metalloproteinase that activates another metalloproteinase, procollagenase, and degrades noncollagenous matrix. We describe the construction of an activator complementary DNA (cDNA) clone, which is 1.9 kb, that selects a 2.1‐kb messenger RNA (mRNA) in Northern blot hybridizations. Nucleic acid sequence studies of the activator cDNA indicate 1) that it encodes protein M r 53,881, 2) that this protein exhibits ˜80% homology with rat transin, an oncogene‐induced protein with a previously unknown function, and 3) that, in the first 172 residues, it is virtually identical to the rabbit metalloproteinase, stromelysin. Homology between rabbit activator and human skin collagenase is approximately 50%. Activator and collagenase mRNA are coordinately regulated; untreated cultures of rabbit synovial fibroblasts produce low levels of each protein, but addition of phorbol myristate acetate (10 –8 M ) results in an increase in mRNA for both proteins by 2.5–5 hours. Adding all‐ trans ‐retinoic acid (10 –6 M) or dexamethasone (10 –7 M) to phorbol‐stimulated cells coordinately suppresses both activator and collagenase mRNA. Our data suggest the existence of coordinately regulated metalloproteinases that are important in the modulation of connective tissue metabolism.