title: Tissue inhibitor of metalloproteinases-3 (TIMP-3) is an extracellular matrix-associated protein with a distinctive pattern of expression in mouse cells and tissues.
abstract: We have isolated cDNA clones corresponding to a novel mouse metalloproteinase inhibitor. Five overlapping cDNA clones contain most of the information for a prominent 4.5-kilobase transcript that was detected in RNA from mouse fibroblasts and adult tissues. Sequence analysis revealed an open reading frame (ORF) for a protein of 212 amino acids that is 80% identical to chicken inhibitor of metalloproteinases-3 (ChIMP-3). The 3'-untranslated sequence also showed remarkable conservation with the chicken gene. The ORF directed the expression of a 24-kDa protein in COS-1 cells that localized to the extracellular matrix (ECM). On the basis of these similarities we propose to identify the new gene as murine tissue inhibitor of metalloproteinases-3 (TIMP-3). Mouse C3H 10T1/2 fibroblasts produced a 24-kDa metalloproteinase inhibitor that also localized to the ECM and was recognized by a polyclonal antibody to ChIMP-3. Like TIMP-1, TIMP-3 was highly inducible in mouse C3H 10T1/2 fibroblasts by phorbol ester (PMA), epidermal growth factor (EGF), and transforming growth factor-beta 1, but nuclear run-on assays showed that the on/off transcription kinetics were faster for TIMP-3 than TIMP-1. A major difference in vitro was the stimulation of expression of TIMP-3 by dexamethasone which inhibits EGF- and PMA-induced TIMP-1 transcription. Also, TIMP-3 showed a distinctive pattern of expression in adult tissues with abundant transcripts detected in kidney, lung, and brain but only low levels detected in bone, a prominent location of TIMP-1 transcripts. We propose that TIMP-3 functions in a tissue-specific fashion as part of an acute response to remodeling stimuli.
authors.affiliation: Department of Pharmacology and Therapeutics, University of Calgary, Alberta, Canada.
authors.forename: K J
authors.initials: KJ
authors.lastname: Leco
authors.forename: R
authors.initials: R
authors.lastname: Khokha
authors.forename: N
authors.initials: N
authors.lastname: Pavloff
authors.forename: S P
authors.initials: SP
authors.lastname: Hawkes
authors.forename: D R
authors.initials: DR
authors.lastname: Edwards
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D003907:Dexamethasone / Q000494:pharmacology; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D005796:Genes; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014018:Tissue Distribution; D019717:Tissue Inhibitor of Metalloproteinase-3; D014158:Transcription, Genetic; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D016326:Extracellular Matrix Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D019717:Tissue Inhibitor of Metalloproteinase-3; D016212:Transforming Growth Factor beta; D003907:Dexamethasone; D013755:Tetradecanoylphorbol Acetate