TY - JOUR
T1 - The Chromokinesin, KLP3A, Drives Mitotic Spindle Pole Separation during Prometaphase and Anaphase and Facilitates Chromatid Motility
AU - Kwon, Mijung
AU - Morales-Mulia, Sandra
AU - Brust-Mascher, Ingrid
AU - Rogers, Gregory C.
AU - Sharp, David J.
AU - Scholey, Jonathan M.
PY - 2004/1
Y1 - 2004/1
N2 - Mitosis requires the concerted activities of multiple microtubule (MT)-based motor proteins. Here we examined the contribution of the chromokinesin, KLP3A, to mitotic spindle morphogenesis and chromosome movements in Drosophila embryos and cultured S2 cells. By immunofluorescence, KLP3A associates with nonfibrous punctae that concentrate in nuclei and display MT-dependent associations with spindles. These punctae concentrate in indistinct domains associated with chromosomes and central spindles and form distinct bands associated with telophase midbodies. The functional disruption of KLP3A by antibodies or dominant negative proteins in embryos, or by RNA interference (RNAi) in S2 cells, does not block mitosis but produces defects in mitotic spindles. Time-lapse confocal observations of mitosis in living embryos reveal that KLP3A inhibition disrupts the organization of interpolar (ip) MTs and produces short spindles. Kinetic analysis suggests that KLP3A contributes to spindle pole separation during the prometaphase-to-metaphase transition (when it antagonizes Ncd) and anaphase B, to normal rates of chromatid motility during anaphase A, and to the proper spacing of daughter nuclei during telophase. We propose that KLP3A acts on MTs associated with chromosome arms and the central spindle to organize ipMT bundles, to drive spindle pole separation and to facilitate chromatid motility.
AB - Mitosis requires the concerted activities of multiple microtubule (MT)-based motor proteins. Here we examined the contribution of the chromokinesin, KLP3A, to mitotic spindle morphogenesis and chromosome movements in Drosophila embryos and cultured S2 cells. By immunofluorescence, KLP3A associates with nonfibrous punctae that concentrate in nuclei and display MT-dependent associations with spindles. These punctae concentrate in indistinct domains associated with chromosomes and central spindles and form distinct bands associated with telophase midbodies. The functional disruption of KLP3A by antibodies or dominant negative proteins in embryos, or by RNA interference (RNAi) in S2 cells, does not block mitosis but produces defects in mitotic spindles. Time-lapse confocal observations of mitosis in living embryos reveal that KLP3A inhibition disrupts the organization of interpolar (ip) MTs and produces short spindles. Kinetic analysis suggests that KLP3A contributes to spindle pole separation during the prometaphase-to-metaphase transition (when it antagonizes Ncd) and anaphase B, to normal rates of chromatid motility during anaphase A, and to the proper spacing of daughter nuclei during telophase. We propose that KLP3A acts on MTs associated with chromosome arms and the central spindle to organize ipMT bundles, to drive spindle pole separation and to facilitate chromatid motility.
UR - http://www.scopus.com/inward/record.url?scp=0347990572&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0347990572&partnerID=8YFLogxK
U2 - 10.1091/mbc.E03-07-0489
DO - 10.1091/mbc.E03-07-0489
M3 - Article
C2 - 14528012
SN - 1059-1524
VL - 15
SP - 219
EP - 233
JO - Molecular biology of the cell
JF - Molecular biology of the cell
IS - 1
ER -