The role of the Kinesin-13 family protein TbKif13-2 in flagellar length control of Trypanosoma brucei

TbKif13-2, a member of the microtubule-depolymerising Kinesin-13 family was localised at the tip of the flagellum in Trypanosoma brucei. Its predicted activity suggested a role in the regulation of axonemal length. However, using gene deletion and overexpression of TbKif13-2 we show that, in procyclic T. brucei, this kinesin has only a very limited effect on flagellar length. Gene deletion resulted in no significant elongation of the flagellum and overexpression only slightly decreased flagellar length and the rate of growth of a new flagellum during cell division. This is in contrast to studies in Leishmania major, where overexpression of the TbKif13-2 homologue resulted in a significant length reduction of the flagellum. Knockout of TbKif13-2 has, however, an effect on the initial growth of the emerging new flagellum. In conclusion, we show that TbKif13-2 has only a marginal impact on flagellar length in T. brucei.

Trypanosoma brucei contains at least five microtubule-depolymerising kinesins, but the flagellar kinesin TbKif13-2 has only a moderate effect on flagellar dynamics.84Research highlights▶ The depolymerising kinesin TbKif13-2 is localised at the tip of the mature and new flagellum of T. brucei. ▶ A gene deletion mutant of this kinesin has no measurable effect on the length of the flagellum. ▶ Overexpression of a myc-tagged TbKif13-2 has marginal, but significant effects on the initial rate of outgrowth of the new flagellum and on the length of the mature flagellum.