Decapping and decay of messenger RNA occur in cytoplasmic processing bodies.
A major pathway of eukaryotic messenger RNA (mRNA) turnover begins with deadenylation, followed by decapping and 5' to 3' exonucleolytic decay. We provide evidence that mRNA decapping and 5' to 3' degradation occur in discrete cytoplasmic foci in yeast, which we call processing bodies (P bodies). First, proteins that activate or catalyze decapping are concentrated in P bodies. Second, inhibiting mRNA turnover before decapping leads to loss of P bodies; however, inhibiting turnover at, or after, decapping, increases the abundance and size of P bodies. Finally, mRNA degradation intermediates are localized to P bodies. These results define the flux of mRNAs between polysomes and P bodies as a critical aspect of cytoplasmic mRNA metabolism and a possible site for regulation of mRNA degradation.
Department of Molecular and Cellular Biology & Howard Hughes Medical Institute, University of Arizona, Tucson, AZ 85721, USA.
Ujwal
U
Sheth
Roy
R
Parker
D036022:Capsid Proteins / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000378:metabolism / Q000648:ultrastructure; D022083:Cytoplasmic Structures / Q000378:metabolism* / Q000648:ultrastructure; D053487:DEAD-box RNA Helicases; D004268:DNA-Binding Proteins / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008954:Models, Biological; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps / Q000378:metabolism*; D020365:RNA Helicases / Q000378:metabolism; D012331:RNA, Fungal / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
D036022:Capsid Proteins; D004268:DNA-Binding Proteins; C114069:LSM1 protein, S cerevisiae; D008164:Luminescent Proteins; C103266:PAT1 protein, S cerevisiae; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; C078657:CCR4 protein, S cerevisiae; C100868:DCP1 protein, S cerevisiae; C400572:DCP2 protein, S cerevisiae; D004722:Endoribonucleases; D012260:Ribonucleases; C445083:DHH1 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases