Research Project: Hücre Döngüsü Protein Dengesinde PI(3,5)P2'nin Moleküler Rolünün Araştırılması
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Contributors
Funders
ID
TB.00504
Authors
Çaydaşı, Ayşe Koca
Faculty Member
Publications
The signalling lipid PI3,5P 2 is essential for timely mitotic exit
(Royal Society Publishing, 2023) Bektaş, Şeyma Nur; Çaydaşı, Ayşe Koca; Huda, Mariam; Bekdaş, Barış; Department of Molecular Biology and Genetics; Graduate School of Sciences and Engineering; Yes; College of Sciences; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING
Coordination of mitotic exit with chromosome segregation is key for successful mitosis. Mitotic exit in budding yeast is executed by the mitotic exit network (MEN), which is negatively regulated by the spindle position checkpoint (SPOC). SPOC kinase Kin4 is crucial for SPOC activation in response to spindle positioning defects. Here, we report that the lysosomal signalling lipid phosphatidylinositol-3,5-bisphosphate (PI3,5P 2) has an unanticipated role in the timely execution of mitotic exit. We show that the lack of PI3,5P 2 causes a delay in mitotic exit, whereas elevated levels of PI3,5P 2 accelerates mitotic exit in mitotic exit defective cells. Our data indicate that PI3,5P 2 promotes mitotic exit in part through impairment of Kin4. This process is largely dependent on the known PI3,5P 2 effector protein Atg18. Our work thus uncovers a novel link between PI3,5P 2 and mitotic exit. © 2023 Royal Society Publishing. All rights reserved.
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.
