Figure 5.

Growth assays show that mutants in the Bub1-Sgo1-H2A cohesion pathway render cells sensitive to NAM. (A) Deletion in BUB1, BUB3, and BUB1 with its kinase domain deleted (bub1KD) all confer sensitivity to 30 mM nicotinamide (NAM). In contrast, deletions in MAD1, MAD2, or MAD3 lead to little to no sensitivity to NAM. Loss of Bub1 kinase activity phenocopies the sensitivity displayed in BUB1 deletion mutants to NAM. (B) The nonphosphorylatable H2A (htaS121A) mutant and deletion in SGO1 both show similar sensitivity to NAM. (C) Deletions in subunits of the alternative replication complex leads to sensitivity to 120 mM NAM. Overnight cultures of each strain were serially diluted fivefold and 3 μl were spotted and incubated at 30°C. WT, wild-type.