H. Wein et al., DSK1, A NOVEL KINESIN-RELATED PROTEIN FROM THE DIATOM CYLINDROTHECA-FUSIFORMIS THAT IS INVOLVED IN ANAPHASE SPINDLE ELONGATION, The Journal of cell biology, 133(3), 1996, pp. 595-604
We have identified an 80-kD protein that is involved in mitotic spindl
e elongation in the diatom Cylindrotheca fusiformis. DSK1 (Diatom Spin
dle Kinesin 1) was isolated using a peptide antibody raised against a
conserved region in the motor domain of the kinesin superfamily. By se
quence homology, DSK1 belongs to the central motor family of kinesin-r
elated proteins. Immunoblots using an antibody raised against a noncon
served region of DSK1 show that DSK1 is greatly enriched in mitotic sp
indle preparations. Anti-DSK1 stains the diatom central spindle with a
bias toward the midzone, and staining is retained in the spindle midz
one during spindle elongation in vitro. Furthermore, preincubation wit
h anti-DSK1 blocks function in an in vitro spindle elongation assay. T
his inhibition of spindle elongation can be rescued by preincubating c
oncurrently with the fusion protein against which anti-DSK1 was raised
. We conclude that DSK1 is involved in spindle elongation and is likel
y to be responsible for pushing half-spindles apart in the spindle mid
zone.