Mammalian Tolloid Metalloproteinase, and Not Matrix Metalloprotease 2 or Membrane Type 1 Metalloprotease, Processes Laminin-5 in Keratinocytes and Skin

• Published in: The Journal of biological chemistry 2003-05, Vol.278 (18), p.15661-15668
• Main Authors: Veitch, Dallas P., Nokelainen, Pasi, McGowan, Kelly A., Nguyen, Thuong-Thuong, Nguyen, Ngon E., Stephenson, Robert, Pappano, William N., Keene, Douglas R., Spong, Suzanne M., Greenspan, Daniel S., Findell, Paul R., Marinkovich, M. Peter
• Format: Article
• Language: English
• Subjects: Bone Morphogenetic Proteins; Cell Adhesion Molecules - chemistry; Cell Adhesion Molecules - metabolism; Cells, Cultured; Fibrinolysin - physiology; Fungal Proteins; Humans; Isoenzymes - physiology; Kalinin; Keratinocytes - metabolism; Matrix Metalloproteinase 14; Matrix Metalloproteinase 2 - physiology; Matrix Metalloproteinases, Membrane-Associated; Metalloendopeptidases - physiology; Metalloproteases; Mitogen-Activated Protein Kinases - physiology; Proteins - physiology; Skin - metabolism; Tolloid-Like Metalloproteinases
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M210588200

Laminin-5, a major adhesive ligand for epithelial cells, undergoes processing of its γ2 and α3 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 γ2 and α3 chains in keratinocyte cultures in a dose-dependent manner. In a proteinase survey, all BMP-1 isoenzymes processed human laminin-5 γ2 and α3 chains to 105- and 165-kDa fragments, respectively. In contrast, MT1-MMP and MMP-2 did not cleave the γ2 chain of human laminin-5 but processed the rat laminin γ2 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 γ2 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.