Mammalian tolloid metalloproteinase, and not matrix metalloprotease 2 or membrane type 1 metalloprotease, processes laminin-5 in keratinocytes and skin.
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.
Veitch
Dallas P
DP
Program in Epithelial Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA.
Nokelainen
Pasi
P
McGowan
Kelly A
KA
Nguyen
Thuong-Thuong
TT
Nguyen
Ngon E
NE
Stephenson
Robert
R
Pappano
William N
WN
Keene
Douglas R
DR
Spong
Suzanne M
SM
Greenspan
Daniel S
DS
Findell
Paul R
PR
Marinkovich
M Peter
MP
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
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