title: CLASPs link focal-adhesion-associated microtubule capture to localized exocytosis and adhesion site turnover.
abstract: Turnover of integrin-based focal adhesions (FAs) with the extracellular matrix (ECM) is essential for coordinated cell movement. In collectively migrating human keratinocytes, FAs assemble near the leading edge, grow and mature as a result of contractile forces and disassemble underneath the advancing cell body. We report that clustering of microtubule-associated CLASP1 and CLASP2 proteins around FAs temporally correlates with FA turnover. CLASPs and LL5β (also known as PHLDB2), which recruits CLASPs to FAs, facilitate FA disassembly. CLASPs are further required for FA-associated ECM degradation, and matrix metalloprotease inhibition slows FA disassembly similarly to CLASP or PHLDB2 (LL5β) depletion. Finally, CLASP-mediated microtubule tethering at FAs establishes an FA-directed transport pathway for delivery, docking and localized fusion of exocytic vesicles near FAs. We propose that CLASPs couple microtubule organization, vesicle transport and cell interactions with the ECM, establishing a local secretion pathway that facilitates FA turnover by severing cell-matrix connections.
authors.affiliation: 1] Department of Cell and Tissue Biology, University of California San Francisco, 513 Parnassus Avenue San Francisco, California 94143, USA [2].
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Stehbens
authors.affiliation: 1] Department of Surgery and Center for Bioengineering and Tissue Regeneration, University of California San Francisco, 513 Parnassus Avenue San Francisco, California 94143, USA [2].
authors.forename: Matthew
authors.initials: M
authors.lastname: Paszek
authors.affiliation: Department of Cell and Tissue Biology, University of California San Francisco, 513 Parnassus Avenue San Francisco, California 94143, USA.
authors.forename: Hayley
authors.initials: H
authors.lastname: Pemble
authors.affiliation: Department of Cell and Tissue Biology, University of California San Francisco, 513 Parnassus Avenue San Francisco, California 94143, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Ettinger
authors.affiliation: Department of Cell and Tissue Biology, University of California San Francisco, 513 Parnassus Avenue San Francisco, California 94143, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Gierke
authors.affiliation: Department of Cell and Tissue Biology, University of California San Francisco, 513 Parnassus Avenue San Francisco, California 94143, USA.
authors.forename: Torsten
authors.initials: T
authors.lastname: Wittmann
mesh_terms: D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D005089:Exocytosis / Q000187:drug effects; D005109:Extracellular Matrix / Q000378:metabolism; D022001:Focal Adhesions / Q000187:drug effects / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D022161:Transport Vesicles / Q000187:drug effects / Q000378:metabolism*
chemical_list: C497850:CLASP1 protein, human; C497851:CLASP2 protein, human; D002352:Carrier Proteins; D008164:Luminescent Proteins; D061965:Matrix Metalloproteinase Inhibitors; D008869:Microtubule-Associated Proteins; C471180:PHLDB2 protein, human; D011993:Recombinant Fusion Proteins; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14