|
|
| J. Biol. Chem. Apr (1994); 269(16):12263-8 | |
| The integrin chains beta 1 and alpha 6 associate with the chaperone calnexin prior to integrin assembly. | |
| Lenter M, Vestweber D | |
| Hans-Spemann Laboratorium am Max-Planck-Institut fur Immunbiologie, Freiburg, Germany. | |
| Abstract: Integrins are alpha beta heterodimers that mediate cell-cell adhesion, as well as cell-substrate adhesion. The largest subclass is formed by 10 heterodimers (the very late antigens) that all share the beta 1-chain. We have found a 90-kDa protein that co-isolates with mouse integrin beta 1-chain. This 90-kDa protein was identified as the mouse homolog of calnexin, a membrane-bound chaperone and resident protein of the endoplasmic reticulum. First, the sequence of the 15 NH2-terminal amino acids of the 90-kDa protein is 80% and 87% identical to the corresponding sequences of canine and human calnexin, respectively. Second, the 90-kDa protein was recognized by a monoclonal antibody against calnexin/IP90. Association of calnexin with the integrin beta 1-chain was directly demonstrated by chemical cross-linking. As pulse-chase experiments revealed, the association of the beta 1-chain with calnexin occurred prior to the assembly with integrin alpha 6-chain. Additionally, the alpha 6-chain bound to calnexin before integrin assembly and dissociated again at the time of integrin-assembly. Our data suggest that calnexin is involved in the assembly of beta 1 integrins, as well as in the retention of a pool of immature integrin beta 1-chains in the ER. | |
| [PUBMED: 8163531] |   |
| Copyright © 2007, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. |
| terms and conditions - privacy policy - Osprey Network Visualization System |
| 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. |