Fission yeast Ase1PRC1 is required for the G2-microtubule damage response

• Published in: Molecular biology research communications 2021-12, Vol.10 (4), p.179-188
• Main Authors: Doss, Rose M, Xhunga, Sindi, Klimczak, Dorothy, Cameron, Molly, Verlare, Jordan, Wolkow, Tom D
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 2322-181X; 2345-2005
• DOI: 10.22099/mbrc.2021.41001.1650

Schizosaccharomyces pombe delays entry into mitosis following G 2 microtubule damage. This pathway is dependent on Rad26 ATRIP , the regulatory subunit of the Rad26 ATRIP /Rad3 ATR DNA damage response (DDR) complex. However, this G 2 microtubule damage response pathway acts independently of the G 2 DNA damage checkpoint pathway. To identify other proteins in this G 2 microtubule damage pathway, we previously screened a cDNA overexpression library for genes that rescued the sensitivity of rad26Δ cells to the microtubule poison thiabendazole. A partial cDNA fragment encoding only the C-terminal regulatory region of the microtubule bundling protein Ase1 PRC1 was isolated. This fragment lacks the Ase1 PRC1 dimerization and microtubule binding domains and retains the conserved C-terminal unstructured regulatory region. Here, we report that ase1Δ cells fail to delay entry into mitosis following G 2 microtubule damage. Microscopy revealed that Rad26 ATRIP foci localized alongside Ase1 PRC1 filaments, although we suggest that this is related to microtubule-dependent double strand break mobility that facilitates homologous recombination events. Indeed, we report that the DNA repair protein Rad52 co-localizes with Rad26 ATRIP at these foci, and that localization of Rad26 ATRIP to these foci depends on a Rad26 ATRIP N-terminal region containing a checkpoint recruitment domain. To our knowledge, this is the first report implicating Ase1 PRC1 in regulation of the G 2 /M transition.