Research Project: Kohezinin mitozdan çıkıştaki beklenmedik rolünün moleküler karakterizasyonu
Loading...
Contributors
Funders
ID
TB.00425
Authors
Çaydaşı, Ayşe Koca
Faculty Member
Publications
PI(3,5)P2 asymmetry during mitosis is essential for asymmetric vacuolar inheritance
(Rockefeller University Press, 2025) Huda, Mariam; Koyuncu, Mukadder; Dilege, Cansu; Çaydaşı, Ayşe Koca; N/A; Department of Molecular Biology and Genetics; Graduate School of Sciences and Engineering; Yes; College of Sciences; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING
Phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) is a low-abundance signaling lipid that plays crucial roles in various cellular processes, including endolysosomal system structure/function, stress response, and cell cycle regulation. PI(3,5)P2 synthesis increases in response to environmental stimuli, yet its behavior in cycling cells under basal conditions remains elusive. Here, we analyzed spatiotemporal changes in PI(3,5)P2 levels during the cell cycle of S. cerevisiae. We found that PI(3,5)P2 accumulates on the vacuole in the daughter cell while it disappears from the vacuole in the mother cell during mitosis. Concomitant with the changes in PI(3,5)P2 distribution, the daughter vacuole became more acidic, whereas the acidity of the mother vacuole decreased during mitosis. Our data further showed that both PI(3,5)P2 and the PI(3,5)P2 effector protein Atg18 are determinants of vacuolar-pH asymmetry and acidity. Our work, thus, identifies PI(3,5)P2 as a key factor for the establishment of vacuolar-pH asymmetry, providing insights into how the mother cell ages while the daughter cell is rejuvenated.
Protein phosphatase 1 in association with Bud14 inhibits mitotic exit in Saccharomyces cerevisiae
(eLife Sciences Publications, 2021) Bektaş, Şeyma Nur; Çaydaşı, Ayşe Koca; Dilege, Cansu; Karabürk, Hüseyin; Kırdök, İdil; Kocakaplan, Dilara; Department of Molecular Biology and Genetics; Graduate School of Sciences and Engineering; Yes; College of Engineering; College of Sciences; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING
Mitotic exit in budding yeast is dependent on correct orientation of the mitotic spindle along the cell polarity axis. When accurate positioning of the spindle fails, a surveillance mechanism named the Spindle Position Checkpoint (SPOC) prevents cells from exiting mitosis. Mutants with a defective SPOC become multinucleated and lose their genomic integrity. Yet, a comprehensive understanding of the SPOC mechanism is missing. In this study, we identified the type 1 protein phosphatase, Glc7, in association with its regulatory protein Bud14 as a novel checkpoint component. We further showed that Glc7-Bud14 promotes dephosphorylation of the SPOC effector protein Bfa1. Our results suggest a model in which two mechanisms act in parallel for a robust checkpoint response: first, the SPOC kinase Kin4 isolates Bfa1 away from the inhibitory kinase Cdc5 and second, Glc7-Bud14 dephosphorylates Bfa1 to fully activate the checkpoint effector.
