Genome-wilde identification of decapping substrates in the yeast Saccharomyces cervisiae

To assess the roles of the Dcp2 C-terminal domain and the decapping activators Pat1, Lsm1, and Dhh1 in mRNA decapping, we used RNA-Seq to analyze the expression profiles of yeast cells harboring a truncation of the Dcp2 C-terminal domain, mutations that render Dcp2 catalytically inactive, or deletions of the PAT1, LSM1, and DHH1 genes. Consistent with our recent model for decapping regulation, we found that: i) the Dcp2 C-terminal domain is an effector of both negative and positive regulation and that loss of these control functions causes significant deregulation of mRNA decapping; ii) rather than being global activators of decapping, Pat1, Lsm1, and Dhh1 directly target specific subsets of yeast mRNAs and loss of the functions of each of these factors has substantial indirect consequences for genome-wide mRNA expression; and iii) transcripts targeted by Pat1, Lsm1, and Dhh1 exhibit only partial overlap and, as expected, are targeted to decapping-dependent decay. Genome-wide expression profiles of the wild-type strain and each of the mutant strains were generated by RNA-Seq, in triplicate, using Illumina HiSeq4000. The transcripts differentially expressed in different mutant cells were identified by comparisons to the transcripts expressed in wild-type cells.