Analysis of P-body assembly in Saccharomyces cerevisiae.
Recent experiments have defined cytoplasmic foci, referred to as processing bodies (P-bodies), that contain untranslating mRNAs in conjunction with proteins involved in translation repression and mRNA decapping and degradation. However, the order of protein assembly into P-bodies and the interactions that promote P-body assembly are unknown. To gain insight into how yeast P-bodies assemble, we examined the P-body accumulation of Dcp1p, Dcp2p, Edc3p, Dhh1p, Pat1p, Lsm1p, Xrn1p, Ccr4p, and Pop2p in deletion mutants lacking one or more P-body component. These experiments revealed that Dcp2p and Pat1p are required for recruitment of Dcp1p and of the Lsm1-7p complex to P-bodies, respectively. We also demonstrate that P-body assembly is redundant and no single known component of P-bodies is required for P-body assembly, although both Dcp2p and Pat1p contribute to P-body assembly. In addition, our results indicate that Pat1p can be a nuclear-cytoplasmic shuttling protein and acts early in P-body assembly. In contrast, the Lsm1-7p complex appears to primarily function in a rate limiting step after P-body assembly in triggering decapping. Taken together, these results provide insight both into the function of individual proteins involved in mRNA degradation and the mechanisms by which yeast P-bodies assemble.
Teixeira
Daniela
D
Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, University of Arizona, Tucson, AZ 85721-0106, USA.
Parker
Roy
R
D003594:Cytoplasmic Granules / Q000378:metabolism*; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012260:Ribonucleases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; C114069:LSM1 protein, S cerevisiae; C103266:PAT1 protein, S cerevisiae; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C078657:CCR4 protein, S cerevisiae; C400572:DCP2 protein, S cerevisiae; D004722:Endoribonucleases; D012260:Ribonucleases; C079009:POP2 protein, S cerevisiae; C445083:DHH1 protein, S cerevisiae; D053487:DEAD-box RNA Helicases