Title

Organization of microtubules by C-terminal kinesin NCD

Date of Completion

January 2007

Keywords

Biology, Cell

Degree

Ph.D.

Abstract

Organization of microtubules is essential for many basic activities of the cell. The establishment of cell structure and polarity, cell differentiation and cell division all are as a result of organized MTs. Microtubules play a vital role in cytoplasmic organization during interphase by forming a radial array of uniform polarity with the minus end at the center and plus end towards the cell periphery; and during mitosis by forming the mitotic spindle, which is responsible for faithful segregation of chromosomes. Microtubule motors have been shown to be major players in the MT organization in interphase and in mitosis. Non-claret disjunctional protein (Ncd) is a C-terminal microtubule motor that moves toward the minus end of microtubules. Along with other mitotic microtubule motors, Ncd generates a pulling force that is critical in the assembly of bipolar mitotic spindle. This pulling force is balanced by the activity of plus-end directed motors of BimC family, and they are both required for the establishment and maintenance of the spindle bipolarity. Although it is suggested that these MT motors perform these functions by inducing sliding of antiparallel MTs outgrowing from spindle poles in opposite directions, such MT sliding has never been demonstrated. The goal of this work is to directly demonstrate in vivo bundling and sliding of microtubules by C-terminal kinesin motor Ncd. ^