More About KSP
Another member of the kinesin superfamily of microtubule-based motors that plays a critical role in the early stages of mitosis as it mediates centrosome separation and bipolar spindle assembly and maintenance, is the Kinesin spindle protein (KSP or Eg5; EC 3.6.4.4). It is a slow, plus end–directed motor of the kinesin-5 subfamily, and forms a homotetrameric structure capable of binding antiparallel microtubules and sliding them apart[1]. Centrosome separation and bipolar spindle assembly are essential for proper segregation of chromosomes. Failure of KSP function, by immunodepletion or knockdown of KSP mRNA by small interfering RNA, leads to cell cycle arrest in mitosis with monoastral microtubule arrays. It is most abundant in proliferating human tissues and is highly expressed in tumors of the breast, colon, lung, ovary, and uterus[2].
[1]D. Huszar et al. Kinesin motor proteins as targets for cancer therapy. Cancer Metastasis Rev. 2009 Jun;28(1-2):197-208.
[2]V. Sarli et al. Targeting the kinesin spindle protein: basic principles and clinical implications. Clin Cancer Res. 2008 Dec 1;14(23):7583-7.