Dynamic localization of CLIP-170 to microtubule plus ends is coupled to microtubule assembly.
CLIP-170 is a cytoplasmic linker protein that localizes to plus ends of microtubules in vivo. In this study, we have characterized the microtubule-binding properties of CLIP-170, to understand the mechanism of its plus end targeting. We show that the NH2-terminal microtubule-interacting domain of CLIP-170 alone localizes to microtubule plus ends when transfected into cells. Association of CLIP-170 with newly-formed microtubules was observed in cells microinjected with biotinylated tubulin, used as a tracer for growing microtubules. Using in vitro assays, association of CLIP-170 with recently polymerized tubulin is also seen. Cross-linking and sedimentation velocity experiments suggest association of CLIP-170 with nonpolymerized tubulin. We conclude from these experiments that the microtubule end targeting of CLIP-170 is closely linked to tubulin polymerization.
Diamantopoulos
G S
GS
Department of Cell Biology, Sciences III, University of Geneva, CH-1211 Geneva 4, Switzerland. diamantopoulos@cellbio.unige.ch
Perez
F
F
Goodson
H V
HV
Batelier
G
G
Melki
R
R
Kreis
T E
TE
Rickard
J E
JE
D018385:Centrosome / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism* / Q000502:physiology; D009363:Neoplasm Proteins; D014404:Tubulin / Q000378:metabolism; D014407:Tumor Cells, Cultured
D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D014404:Tubulin; C076744:cytoplasmic linker protein 170; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C004805:5'-guanylylmethylenebisphosphonate; D006160:Guanosine Triphosphate