The Putative RNA-Binding Protein Dri1 Promotes the Loading of Kinesin-14/Klp2 to the Mitotic Spindle and Is Sequestered into Heat-Induced Protein Aggregates in Fission Yeast

Cells form a bipolar spindle during mitosis to ensure accurate chromosome segregation. Proper architecture is established by set of kinesin motors and microtubule-associated proteins. In most eukaryotes, kinesin-5 are essential for this process, genetic or chemical inhibition their activity leads the emergence monopolar spindles cell death. However, these deficiencies can be rescued simultaneous inactivation kinesin-14 motors, as they counteract kinesin-5. We conducted detailed analyses in fission yeast understand mechanisms driving assembly absence Here, we show that deletion dri1 gene, which encodes putative RNA-binding protein, rescue temperature sensitivity caused cut7-22, mutant. Interestingly, kinesin-14/Klp2 levels on cut7 mutants were significantly reduced deletion, although total Klp2 stability microtubules remained unaffected. Moreover, motifs Dri1 its cytoplasmic localization function. have also found portion spatially functionally sequestered chaperone-based protein aggregates upon mild heat stress limits division at high temperatures. propose might involved post-transcriptional regulation through ability promote loading microtubules.