Cohesin dysfunction results in cell wall defects in budding yeast

Abstract

Cohesin is a conserved chromatin-binding multisubunit protein complex involved in diverse chromosomal transactions such as sister-chromatid cohesion, chromosome condensation, regulation of gene expression, DNA replication, and repair. While working with a budding yeast temperature-sensitive mutant, mcd1-1, defective in a cohesin subunit, we observed that it was resistant to zymolyase, indicating an altered cell wall organization. The budding yeast cell wall is a strong but elastic structure essential for maintenance of cell shape and protection from extreme environmental challenges. Here, we show that the cohesin complex plays an important role in cell wall maintenance. Cohesin mutants showed high chitin content in the cell wall and sensitivity to multiple cell wall stress-inducing agents. Interestingly, temperature-dependent lethality of cohesin mutants was osmoremedial, in a HOG1-MAPK pathway-dependent manner, suggesting that the temperature sensitivity of these mutants may arise partially from cell wall defects. Moreover, Mpk1 hyper-phosphorylation indicated activation of the cell wall integrity (CWI) signaling pathway in cohesin mutants. Genetic interaction analysis revealed that the CWI pathway is essential for survival of mcd1-1 upon additional cell wall stress. The cell wall defect was independent of the cohesion function and accompanied by misregulation of expression of several genes having cell wall-related functions. Our findings reveal a requirement of cohesin in maintenance of CWI that is independent of the CWI pathway, and that may arise from cohesin’s role in regulating the expression of multiple genes encoding proteins involved in cell wall organization and biosynthesis.

Structural Maintenance of Chromosome 3 interacts with the Topoisomerase VI complex and contributes to the oxidative stress response inArabidopsis thaliana

“…For instance, in Cornelia de Lange Syndrome, cell lines carrying mutations in SMC1A or SMC3 exhibit higher level of protein carbonylation, reflecting increased global oxidative stress (Gimigliano et al ., 2012). In budding yeast, temperature sensitive mutants of the cohesin complex show induction of the cell wall stress responsive genes CHITIN SYNTHASE 3 ( CHS3 ) and the β-1,3-GLUCAN SYNTHASE ( FKS2 ), display increased amount of chitin in their cell wall, and are sensitive to cell wall stress-inducing agents (Kothiwal, Gopinath and Laloraya, 2021). Finally, in embryonic stem cells, the cohesin complex was reported to participate in the establishment of the heat stress response by modifying the local chromatin architecture around heat stress-activated enhancers (Lyu, Rowley and Corces, 2018).…”