Transient Breakage of the Nucleocytoplasmic Barrier Controls Spore Maturation via Mobilizing the Proteasome Subunit Rpn11 in the Fission Yeast Schizosaccharomyces pombe

• Published in: Journal of fungi (Basel) Vol. 6; no. 4; p. 242
• Main Authors: Yang, Hui-Ju, Asakawa, Haruhiko, Ohtsuki, Chizuru, Haraguchi, Tokuko, Hiraoka, Yasushi
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 23.10.2020; MDPI AG
• Subjects: anaphase-promoting complex (APC/C); forespore membrane; leading-edge protein (LEP); meiosis; meu14; proteasome; proteasome; meiosis; leading-edge protein (LEP); virtual nuclear envelope breakdown (vNEBD); rpn11; forespore membrane; anaphase-promoting complex (APC/C); meu14
• ISSN: 2309-608X; 2309-608X
• DOI: 10.3390/jof6040242

Forespore membrane (FSM) closure is a process of specialized cytokinesis in yeast meiosis. FSM closure begins with the contraction of the FSM opening and finishes with the disassembly of the leading-edge proteins (LEPs) from the FSM opening. Here, we show that the FSM opening starts to contract when the event of virtual nuclear envelope breakdown (vNEBD) occurs in anaphase II of the fission yeast . The occurrence of vNEBD controls the redistribution of the proteasomal subunit Rpn11 from the nucleus to the cytosol. To investigate the importance of Rpn11 re-localization during vNEBD, Rpn11 was sequestered at the inner nuclear membrane by fusion with the transmembrane region of Bqt4 (Rpn11-GFP-INM). Remarkably, in the absence of endogenous , the cells carrying Rpn11-GFP-INM had abnormal or no spore formation. Live-cell imaging analysis further reveals that the FSM opening failed to contract when vNEBD occurred, and the LEP Meu14 was persistently present at the FSM in the INM cells. The results suggest that the dynamic localization of Rpn11 during vNEBD is essential for spore development.