Department of Biological Sciences, The University of Hull
Abstract
Kinesins are motor proteins involved in the movement of organelles and sub-organelles along microtubule tracks within the cell. Phylogenetic analysis of the 46 kinesin genes coded by the Trypanosoma brucei genome resulted in the grouping of seven kinesin sequences into the Kinesin-13 family. Members of this family have been characterised in a number of model organisms and, unlike most kinesins, do not exhibit microtubule processivity and are capable of depolymerising microtubules. They play important roles in bipolar spindle assembly and chromosome segregation. Of the six T. brucei Kinesin-13 proteins that were characterised during this study, only one was found to have a nuclear localisation, while the rest were found localised to the mitochondrion, cell body or flagellum. Attempts to probe the function of these kinesins using RNAi resulted in a reduction of cell growth in three of the six kinesins studied, but no gross changes in cellular morphology were observed. The distinct localisation of five Kinesin-13 family members outside the nucleus suggests that the functional diversity of the Kinesin-13 family is larger than previously thought
