The γ-tubulin complex protein GCP6 in crucial for spindle morphogenesis but not essential for microtubule reorganization in Arabidopsis (OA)

During cell division, cells require to form mitotic spindle and these mitotic spindles are basically newly formed microtubules. The formation of new microtubules depends on γ-tubulin. Along with 5 GPCs (γ-tubulin protein complex), γ-tubulin form γTuRC (γ-tubulin ring complex) and it facilitates the microtubule nucleation. Interestingly, in plant cells, microtubules are nucleated and organized without centrosome. In this article, Miao et al. investigated whether γTuRC is the only functional form of γ-tubulin for microtubule nucleation or another nucleation mechanism that exists in the plant cell. To test this idea, they have used the GPC6, which plays a major role as γTuRC protein in animal and fungal system, mutant (gpc6) in Arabidopsis thaliana and studied the mitotic division in detail. Surprisingly, they have found that although gpc6 mutant has a defect in γ-tubulin localization in microtubule array during mitotic division, these cells successfully complete cell division. This study indicates the major role of γTuRC for microtubule organization and provides insight about γTuRC-independent microtubule organization during mitotic division as well. (Summary by Arif Ashraf) PNAS 10.1073/pnas.1912240116