Phosphorylation regulates targeting of cytoplasmic dynein to kinetochores during mitosis.
Cytoplasmic dynein functions at several sites during mitosis; however, the basis of targeting to each site remains unclear. Tandem mass spectrometry analysis of mitotic dynein revealed a phosphorylation site in the dynein intermediate chains (ICs) that mediates binding to kinetochores. IC phosphorylation directs binding to zw10 rather than dynactin, and this interaction is needed for kinetochore dynein localization. Phosphodynein associates with kinetochores from nuclear envelope breakdown to metaphase, but bioriented microtubule (MT) attachment and chromosome alignment induce IC dephosphorylation. IC dephosphorylation stimulates binding to dynactin and poleward streaming. MT depolymerization, release of kinetochore tension, and a PP1-gamma mutant each inhibited IC dephosphorylation, leading to the retention of phosphodynein at kinetochores and reduced poleward streaming. The depletion of kinetochore dynactin by moderate levels of p50(dynamitin) expression disrupted the ability of dynein to remove checkpoint proteins by streaming at metaphase but not other aspects of kinetochore dynein activity. Together, these results suggest a new model for localization of kinetochore dynein and the contribution of kinetochore dynactin.
Whyte
Jacqueline
J
Department of Biological Sciences and 2Notre Dame Integrated Imaging Facility, University of Notre Dame, Notre Dame, IN 46556, USA.
Bader
Jason R
JR
Tauhata
Sinji B F
SB
Raycroft
Maurice
M
Hornick
Jessica
J
Pfister
K Kevin
KK
Lane
William S
WS
Chan
Gordon K
GK
Hinchcliffe
Edward H
EH
Vaughan
Patricia S
PS
Vaughan
Kevin T
KT
D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D020090:Chromosome Segregation; D003593:Cytoplasm / Q000378:metabolism*; D003595:Cytoplasmic Streaming; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D009154:Mutation; D010766:Phosphorylation; D054645:Protein Phosphatase 1 / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
D002868:Chromosomal Proteins, Non-Histone; C000606361:DCTN2 protein, human; D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; C488261:ZW10 protein, human; D054645:Protein Phosphatase 1; D004398:Dyneins