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| J. Biol. Chem. Jul (2000); 275(30):22728-35 | |
| Bone morphogenetic protein 1 is an extracellular processing enzyme of the laminin 5 gamma 2 chain. | |
| Amano S, Scott IC, Takahara K, Koch M, Champliaud MF, Gerecke DR, Keene DR, Hudson DL, Nishiyama T, Lee S, Greenspan DS, Burgeson RE | |
| MGH/Harvard Cutaneous Biology Research Center, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA. | |
| Abstract: Epithelial cells maintained in culture medium containing low calcium proteolytically process laminin 5 (alpha3beta3gamma2) within the alpha3 and gamma2 chains (). Experiments were designed to identify the enzyme(s) responsible for the laminin 5 processing and the sites of proteolytic cleavage. To characterize the nature of laminin 5 processing, we determined the N-terminal amino acid sequences of the proteolytic fragments produced by the processing events. The results indicate that the first alpha3 chain cleavage (200-l65 kDa alpha3) occurs within subdomain G4 of the G domain. The second cleavage (l65-l45 kDa alpha3) occurs within the lIla domain, 11 residues N-terminal to the start of domain II. The gamma chain is cleaved within the second epidermal growth factor-like repeat of domain Ill. The sequence cleaved within the gamma2 chain matches the consensus sequence for the cleavage of type I, II, and III procollagens by bone morphogenetic protein-1 (BMP-1), also known as type I procollagen C-proteinase (). Recombinant BMP-1 cleaves gamma2 in vitro, both within intact laminin 5 and at the predicted site of a recombinant gamma2 short arm. alpha3 is also cleaved by BMP-1 in vitro, but the cleavage site is yet to be determined. These results show the laminin alpha3 and gamma2 chains to be substrates for BMP-1 in vitro. We speculate that gamma2 cleavage is required for formation of the laminin 5-6 complex and that this complex is directly involved in assembly of the interhemidesmosomal basement membrane. This further suggests that BMP-1 activity facilitates basement membrane assembly, but not hemidesmosome assembly, in the laminin 5-rich dermal-epidermal junction basement membrane in vivo. | |
| [PUBMED: 10806203] |   |
| Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. |
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| BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9. |