A coadapted KNL1 and spindle assembly checkpoint axis orchestrates precise mitosis in Arabidopsis

• DOI: 10.1073/pnas.2316583121
• Publication Date: 2024-01-03T18:44:21Z
• Authors: Xingguang Deng; Ying He; Xiaoya Tang; Xianghong Liu; Yuh-Ru Julie Lee; Bo Liu; Honghui Lin
• Keywords: Spindle checkpoint

The kinetochore scaffold 1 (KNL1) protein recruits spindle assembly checkpoint (SAC) proteins to ensure accurate chromosome segregation during mitosis. Despite such a conserved function among eukaryotic organisms, its molecular architectures have rapidly evolved so that the functional mode of plant KNL1 is largely unknown. To understand how SAC signaling regulated at kinetochores, we characterized gene in Arabidopsis thaliana . was detected kinetochores throughout mitotic cell cycle, and null knl1 mutants were viable fertile but exhibited severe vegetative reproductive defects. mutant cells showed serious impairments congression segregation, resulted formation micronuclei. In absence KNL1, core no longer not activated by unattached or misaligned chromosomes. interacted with essential BUB3.3 BMF3 through specific regions found known other species, recruited them independently kinetochores. Furthermore, demonstrated upon ectopic expression, homolog from dicot tomato able functionally substitute A , while others monocot rice moss associated functional, as reflected sequence variations different lineages. Our results brought insights into understanding rapid evolution lineage-specific connection between molecules.