Identification and analysis of the interaction between Edc3 and Dcp2 in Saccharomyces cerevisiae.
Cap hydrolysis is a critical control point in the life of eukaryotic mRNAs and is catalyzed by the evolutionarily conserved Dcp1-Dcp2 complex. In Saccharomyces cerevisiae, decapping is modulated by several factors, including the Lsm family protein Edc3, which directly binds to Dcp2. We show that Edc3 binding to Dcp2 is mediated by a short peptide sequence located C terminal to the catalytic domain of Dcp2. This sequence is required for Edc3 to stimulate decapping activity of Dcp2 in vitro, for Dcp2 to efficiently accumulate in P-bodies, and for efficient degradation of the RPS28B mRNA, whose decay is enhanced by Edc3. In contrast, degradation of YRA1 pre-mRNA, another Edc3-regulated transcript, occurs independently from this region, suggesting that the effect of Edc3 on YRA1 is independent of its interaction with Dcp2. Deletion of the sequence also results in a subtle but significant defect in turnover of the MFA2pG reporter transcript, which is not affected by deletion of EDC3, suggesting that the region affects some other aspect of Dcp2 function in addition to binding Edc3. These results raise a model for Dcp2 recruitment to specific mRNAs where regions outside the catalytic core promote the formation of different complexes involved in mRNA decapping.
Harigaya
Yuriko
Y
Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, University of Arizona, Tucson, Arizona 85721-0106, USA.
Jones
Brittnee N
BN
Muhlrad
Denise
D
Gross
John D
JD
Parker
Roy
R
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D017124:Conserved Sequence; D022083:Cytoplasmic Structures / Q000378:metabolism; D004722:Endoribonucleases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D012322:RNA Precursors / Q000378:metabolism; D020871:RNA Stability; D016601:RNA-Binding Proteins / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
D000596:Amino Acids; C488957:EDC3 protein, S cerevisiae; D009687:Nuclear Proteins; D012322:RNA Precursors; D016601:RNA-Binding Proteins; C486167:RPS28B protein, S cerevisiae; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C105887:YRA1 protein, S cerevisiae; C400572:DCP2 protein, S cerevisiae; D004722:Endoribonucleases