Nanometer targeting of microtubules to focal adhesions.
Although cell movement is driven by actin, polarization and directional locomotion require an intact microtubule cytoskeleton that influences polarization by modulating substrate adhesion via specific targeting interactions with adhesion complexes. The fidelity of adhesion site targeting is precise; using total internal reflection fluorescence microscopy (TIRFM), we now show microtubule ends (visualized by incorporation of GFP tubulin) are within 50 nm of the substrate when polymerizing toward the cell periphery, but not when shrinking from it. Multiple microtubules sometimes followed similar tracks, suggesting guidance along a common cytoskeletal element. Use of TIRFM with GFP- or DsRed-zyxin in combination with either GFP-tubulin or GFP-CLIP-170 further revealed that the polymerizing microtubule plus ends that tracked close to the dorsal surface consistently targeted substrate adhesion complexes. This supports a central role for the microtubule tip complex in the guidance of microtubules into adhesion foci, and provides evidence for an intimate cross-talk between microtubule tips and substrate adhesions in the range of molecular dimensions.
Krylyshkina
Olga
O
Institute of Molecular Biology, Salzburg A5020, Austria.
Anderson
Kurt I
KI
Kaverina
Irina
I
Upmann
Irene
I
Manstein
Dietmar J
DJ
Small
J Victor
JV
Toomre
Derek K
DK
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism*; D005057:Eukaryotic Cells / Q000166:cytology / Q000378:metabolism*; D022001:Focal Adhesions / Q000378:metabolism*; D006054:Goldfish; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D015394:Molecular Structure; D009363:Neoplasm Proteins; D011108:Polymers / Q000378:metabolism; D011993:Recombinant Fusion Proteins; D014404:Tubulin / Q000378:metabolism
D008164:Luminescent Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D011108:Polymers; D011993:Recombinant Fusion Proteins; D014404:Tubulin; D049452:Green Fluorescent Proteins; C076744:cytoplasmic linker protein 170