Distinct mechanisms govern the localisation of Drosophila CLIP-190 to unattached kinetochores and microtubule plus-ends.
CLIP-170 was the first microtubule plus-end-tracking protein to be described, and is implicated in the regulation of microtubule plus-ends and their interaction with other cellular structures. Here, we have studied the cell-cycle-dependent mechanisms which localise the sole Drosophila melanogaster homologue CLIP-190. During mitosis, CLIP-190 localises to unattached kinetochores independently of spindle-checkpoint activation. This localisation depends on the dynein-dynactin complex and Lis1 which also localise to unattached kinetochores. Further analysis revealed a hierarchical dependency between the proteins with respect to their kinetochore localisation. An inhibitor study also suggested that the motor activity of dynein is required for the removal of CLIP-190 from attached kinetochores. In addition, we found that CLIP-190 association to microtubule plus-ends is regulated during the cell cycle. Microtubule plus-end association is strong in interphase and greatly attenuated during mitosis. Another microtubule plus-end tracking protein, EB1, directly interacts with the CAP-Gly domain of CLIP-190 and is required to localise CLIP-190 at microtubule plus-ends. These results indicate distinct molecular requirements for CLIP-190 localisation to unattached kinetochores in mitosis and microtubule ends in interphase.
Dzhindzhev
Nikola S
NS
The Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3JR, UK.
Rogers
Stephen L
SL
Vale
Ronald D
RD
Ohkura
Hiroyuki
H
D000818:Animals; D002478:Cells, Cultured; D004330:Drosophila; D029721:Drosophila Proteins; D000072159:Dynactin Complex; D004398:Dyneins / Q000037:antagonists & inhibitors / Q000378:metabolism; D018816:Genes, cdc / Q000502:physiology; D007399:Interphase / Q000502:physiology; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology*; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D008941:Spindle Apparatus / Q000378:metabolism*
D029721:Drosophila Proteins; D000072159:Dynactin Complex; C513192:Lis-1 protein, Drosophila; D008869:Microtubule-Associated Proteins; C110769:cytoplasmic linker protein 190; D004398:Dyneins