chromokinesin is a developmentally down-regulated gene with specific e
xpression in proliferating cells during embryonic chick development. I
t encodes a DNA-binding motor protein localized along the chromosome a
rm during mitosis, suggesting that the protein may be a component of t
he long-observed, yet poorly understood 'ejection force' hypothesized
to be involved in controlling the direction and speed of chromosome mo
vement. We have isolated human chromokinesin; with affinity-purified a
ntibodies we demonstrated immunocytochemically that Chromokinesin was
present at a much higher level in cultured retinoblastoma cells than i
n primary cultures of human dermal fibroblasts. The increase in immuno
reactivity was particularly prominent in interphase cells, whereas in
primary cultures of fibroblasts immunopositive cells were predominantl
y M-phase cells. These observations imply a deregulation of chromokine
sin in retinoblastoma cells. Data presented here may be useful in desi
gning strategies to modulate chromosome movement and cell proliferatio
n with either antisense oligonucleotides or specific antibodies, and h
ence may set the stage for further investigations of the involvement o
f chromosome motor molecules in mitosis under normal and pathological
conditions. (C) 1997 Elsevier Science B.V.