title: Dimerization of MT1-MMP during cellular invasion detected by fluorescence resonance energy transfer.
abstract: Homodimerization of the membrane-bound collagenase MT1-MMP [membrane-type 1 MMP (matrix metalloproteinase)] is crucial for its collagenolytic activity. However, it is not clear whether this dimerization is regulated during cellular invasion into three-dimensional collagen matrices. To address this question, we established a fluorescence resonance energy transfer system to detect MT1-MMP dimerization and analysed the process in cells invading through three-dimensional collagen. Our data indicate that dimerization occurs dynamically and constantly at the leading edge of migrating cells, but not the trailing edge. We found that polarized dimerization was not due to ECM (extracellular matrix) attachment, but was rather controlled by reorganization of the actin cytoskeleton by the small GTPases, Cdc42 (cell division cycle 42) and Rac1. Our data indicate that cell-surface collagenolytic activity is regulated co-ordinately with cell migration events to enable penetration of the matrix physical barrier.
authors.affiliation: The Kennedy Institute of Rheumatology, Imperial College London, London W6 8LH, UK. y.itoh@imperial.ac.uk
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Itoh
authors.forename: Ralf
authors.initials: R
authors.lastname: Palmisano
authors.forename: Narayanapanicker
authors.initials: N
authors.lastname: Anilkumar
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nagase
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miyawaki
authors.forename: Motoharu
authors.initials: M
authors.lastname: Seiki
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement; D003094:Collagen / Q000378:metabolism; D057075:Enzyme Assays; D005109:Extracellular Matrix / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D055503:Protein Multimerization; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D059010:Single-Cell Analysis; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: C107953:RAC1 protein, human; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D003094:Collagen; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14; D020764:cdc42 GTP-Binding Protein; D020830:rac1 GTP-Binding Protein