Absence of Caf130 or Yjr011c suppresses the ∆acl4 growth defect by increasing RPL4 mRNA levels.. Delta acl4 suppressors

Genome-wide sequencing of spontaneous suppressors of the slow-growth phenotype of Δacl4 cells identified 47 different mutations, which map to CAF130 (35 mutations), YJR011C/CAL4 (7 mutations), NOT1 (4 mutations), and RPL4A (1 mutation). Since mild overexpression of Rpl4 already efficiently restores the ∆acl4 growth defect and two of the identified suppressor genes, CAF130 and NOT1, encode components of the Ccr4-Not complex, which is implicated in virtually all aspects of mRNA metabolism, the suppression mechanism likely involves an up-regulation of RPL4 mRNA levels. RNA-seq experiments performed with seven different deletion strains (Δcaf130, Δyjr011c, Δbtt1, Δegd1, Δbtt1/Δegd1, Δegd2, and Δacl4) confirmed that RPL4 mRNA levels are higher in strains lacking Caf130 and Yjr011c compared to isogenic wild-type cells.