MKLP2 walks along microtubules and takes the CPC along for a ride

ABSTRACT: The mitotic kinesin-like Protein 2 (MKLP2, KIF20A) is essential for the proper execution of cytokinesis and required to ‘passage’ the chromosomal passenger complex (CPC) from the chromosomes in (pro)metaphase to the spindle midzone and equatorial cortex in anaphase. Together with MKLP1 (KIF23) and MPP1 (KIF20B), MKLP2 forms the kinesin-6 subfamily of motor proteins. Whilst MKLP1 and MPP1 are both plus-end directed processive motors, the typical structure of the MKLP2 motor domain along with the extended neck-linker region, suggested that MKLP2 might not be able to function as a transport motor but is more likely to act as a microtubule bundler. This notion contradicts the prevailing hypothesis that MKLP2 can transport the CPC in anaphase, but appears to be in line with in vitro and in cellulo studies showing that recombinant MKLP2 efficiently bundles microtubules, and that knock-down of MKLP2, disturbs the organization of the anaphase spindle midzone. Using TIRF microscopy and purified fluorescent proteins, we here demonstrate that MKLP2 is a plus-end directed processive motor that can transport the CPC along microtubules in vitro. Live imaging of MKLP2::GFP and INCENP::GFP in early anaphase cells revealed that a fraction of both MKLP2 and INCENP displays directed movements towards the (equatorial) cortex. In line, inhibition of MKLP2 ATPase activity at the start of anaphase disturbed the localization of MKLP2 and CPC at the equatorial cortex. Our data suggest that MKLP2 is a processive microtubule-based motor that transports itself and the CPC to the equatorial cortex.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Diploid Cell

SUBMITTER: Harmjan Vos  

LAB HEAD: Susanne M. A. Lens

PROVIDER: PXD014665 | Pride | 2020-06-10

REPOSITORIES: Pride