Ncd regulation reveals a new mechanism for targeting proteins to the meiotic spindle in oocytes

ABSTRACT: The meiotic spindle in oocytes is formed without centrosomes. How a bipolar spindle is assembled and maintained around chromosomes in oocytes remains to be established. Multiple kinases are known to regulate the meiotic spindle, but how they execute their function is poorly understood. We found that the phospho-docking protein 14-3-3ε, together with the other isoform ζ, stabilises spindle bipolarity in Drosophila oocytes. A critical 14-3-3 target is the minus-end directed motor Ncd (human HSET; kinesin-14) which has well documented roles in stabilising a bipolar spindle in oocytes. Phospho-docking by 14-3-3 inhibits the microtubule binding activity of the non-motor Ncd tail. Further phosphorylation by Aurora B kinase can release Ncd from this inhibitory effect of 14-3-3. As Aurora B localises to chromosomes and spindles, 14-3-3 facilitates specific association of Ncd with spindle microtubules by preventing Ncd from binding to non-spindle microtubules in oocytes. Therefore, 14-3-3 translates a spatial cue provided by Aurora B to target Ncd selectively to the spindle within the large volume of oocytes.  

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Drosophila Melanogaster (fruit Fly)

TISSUE(S): Oocyte

SUBMITTER: Robin Beaven  

LAB HEAD: Hiro Ohkura

PROVIDER: PXD006080 | Pride | 2017-08-29

REPOSITORIES: Pride