In:
The Journal of Cell Biology, Rockefeller University Press, Vol. 180, No. 3 ( 2008-02-11), p. 493-506
Kurzfassung:
Nucleocytoplasmic transport factors mediate various cellular processes, including nuclear transport, spindle assembly, and nuclear envelope/pore formation. In this paper, we identify the chromokinesin human kinesin-like DNA binding protein (hKid) as an import cargo of the importin-α/β transport pathway and determine its nuclear localization signals (NLSs). Upon the loss of its functional NLSs, hKid exhibited reduced interactions with the mitotic chromosomes of living cells. In digitonin-permeabilized mitotic cells, hKid was bound only to the spindle and not to the chromosomes themselves. Surprisingly, hKid bound to importin-α/β was efficiently targeted to mitotic chromosomes. The addition of Ran–guanosine diphosphate and an energy source, which generates Ran–guanosine triphosphate (GTP) locally at mitotic chromosomes, enhanced the importin-β–mediated chromosome loading of hKid. Our results indicate that the association of importin-β and -α with hKid triggers the initial targeting of hKid to mitotic chromosomes and that local Ran-GTP–mediated cargo release promotes the accumulation of hKid on chromosomes. Thus, this study demonstrates a novel nucleocytoplasmic transport factor–mediated mechanism for targeting proteins to mitotic chromosomes.
Materialart:
Online-Ressource
ISSN:
1540-8140
,
0021-9525
DOI:
10.1083/jcb.200708003
Sprache:
Englisch
Verlag:
Rockefeller University Press
Publikationsdatum:
2008
ZDB Id:
1421310-2
SSG:
12
