title: Mammalian tolloid metalloproteinase, and not matrix metalloprotease 2 or membrane type 1 metalloprotease, processes laminin-5 in keratinocytes and skin.
abstract: Laminin-5, a major adhesive ligand for epithelial cells, undergoes processing of its gamma2 and alpha3 chains. This study investigated the mechanism of laminin-5 processing by keratinocytes. BI-1 (BMP-1 isoenzyme inhibitor-1), a selective inhibitor of a small group of astacin-like metalloproteinases, which includes bone morphogenetic protein 1 (BMP-1), mammalian Tolloid (mTLD), mammalian Tolloid-like 1 (mTLL-1), and mammalian Tolloid-like 2 (mTLL-2), inhibited the processing of laminin-5 gamma2 and alpha3 chains in keratinocyte cultures in a dose-dependent manner. In a proteinase survey, all BMP-1 isoenzymes processed human laminin-5 gamma2 and alpha3 chains to 105- and 165-kDa fragments, respectively. In contrast, MT1-MMP and MMP-2 did not cleave the gamma2 chain of human laminin-5 but processed the rat laminin gamma2 chain to an 80-kDa fragment. An immunoblot and quantitative PCR survey of the BMP-1 isoenzymes revealed expression of mTLD in primary keratinocyte cultures but little or no expression of BMP-1, mTLL-1, or mTLL-2. mTLD was shown to cleave the gamma2 chain at the same site as the previously identified BMP-1 cleavage site. In addition, mTLD/BMP-1 null mice were shown to have deficient laminin-5 processing. Together, these data identify laminin-5 as a substrate for mTLD, suggesting a role for laminin-5 processing by mTLD in the skin.
authors.affiliation: Program in Epithelial Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA.
authors.forename: Dallas P
authors.initials: DP
authors.lastname: Veitch
authors.forename: Pasi
authors.initials: P
authors.lastname: Nokelainen
authors.forename: Kelly A
authors.initials: KA
authors.lastname: McGowan
authors.forename: Thuong-Thuong
authors.initials: TT
authors.lastname: Nguyen
authors.forename: Ngon E
authors.initials: NE
authors.lastname: Nguyen
authors.forename: Robert
authors.initials: R
authors.lastname: Stephenson
authors.forename: William N
authors.initials: WN
authors.lastname: Pappano
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Keene
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Spong
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Greenspan
authors.forename: Paul R
authors.initials: PR
authors.lastname: Findell
authors.forename: M Peter
authors.initials: MP
authors.lastname: Marinkovich
mesh_terms: D019485:Bone Morphogenetic Proteins; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism*; D002478:Cells, Cultured; D005341:Fibrinolysin / Q000502:physiology; D005656:Fungal Proteins; D006801:Humans; D007527:Isoenzymes / Q000502:physiology; D015603:Keratinocytes / Q000378:metabolism*; D053511:Matrix Metalloproteinase 14; D020778:Matrix Metalloproteinase 2 / Q000502:physiology*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000502:physiology*; D045726:Metalloproteases; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D011506:Proteins / Q000502:physiology*; D012867:Skin / Q000378:metabolism*; D055394:Tolloid-Like Metalloproteinases; D000097794:Kalinin
chemical_list: D019485:Bone Morphogenetic Proteins; D015815:Cell Adhesion Molecules; D005341:Fibrinolysin; D005656:Fungal Proteins; D007527:Isoenzymes; D053511:Matrix Metalloproteinase 14; D020778:Matrix Metalloproteinase 2; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D045726:Metalloproteases; D020928:Mitogen-Activated Protein Kinases; D011506:Proteins; D055394:Tolloid-Like Metalloproteinases; D000097794:Kalinin; C507096:Mmp14 protein, mouse; C504336:Tll1 protein, rat; C102726:Pmk1 protein, Magnaporthe grisea; C484478:TLL1 protein, human; C485669:TLL2 protein, human; C484477:Tll1 protein, mouse