Evidence of kinesin motors involved in stable kinetochore assembly during early meiosis

• Published in: Molecular biology of the cell 2023-10, Vol.34 (11), p.mbcE22120569-ar107
• Main Authors: Shah, Seema, Mittal, Priyanka, Kumar, Deepanshu, Mittal, Anjani, Ghosh, Santanu K
• Format: Article
• Language: English
• Subjects: Brewer's yeast; Kinesin; Kinetochores; Physiological aspects
• ISSN: 1059-1524; 1939-4586
• DOI: 10.1091/MBC.E22-12-0569

During mitosis, the budding yeast, kinetochores remain attached to microtubules, except for a brief period during S phase. Sister-kinetochores separate into two clusters (bi-lobed' organization) upon stable end-on attachment to microtubules emanating from opposite spindle poles. However, in meiosis, the outer kinetochore protein Ndc80 reassembles at the centromeres much later after prophase I, establishing new kinetochore-microtubule attachments. Perhaps due to this, despite homolog bi-orientation, we observed that the kinetochores (Ndc80) are linearly dispersed between spindle-poles during metaphase I of meiosis. The presence of end-on attachment marker Dam1 as a cluster near each pole suggests one of the other possibilities that the pole-proximal and pole-distal kinetochores are attached end-on and laterally to the microtubules, respectively. Colocalization studies of kinetochores and kinesin motors suggest that budding yeast kinesin 5, Cin8 and Kip1 perhaps localize to the end-on attached kinetochores while kinesin 8, Kip3 resides at all the kinetochores. Our findings, including kinesin 5 and Ndc80 co-appearance after prophase I and reduced Ndc80 levels in null mutant, suggest that kinesin motors are crucial for kinetochore reassembly and stability during early meiosis. Thus, this work reports yet another meiosis specific function of kinesin motors.