Deadenylation is prerequisite for P-body formation and mRNA decay in mammalian cells.
Deadenylation is the major step triggering mammalian mRNA decay. One consequence of deadenylation is the formation of nontranslatable messenger RNA (mRNA) protein complexes (messenger ribonucleoproteins [mRNPs]). Nontranslatable mRNPs may accumulate in P-bodies, which contain factors involved in translation repression, decapping, and 5'-to-3' degradation. We demonstrate that deadenylation is required for mammalian P-body formation and mRNA decay. We identify Pan2, Pan3, and Caf1 deadenylases as new P-body components and show that Pan3 helps recruit Pan2, Ccr4, and Caf1 to P-bodies. Pan3 knockdown causes a reduction of P-bodies and has differential effects on mRNA decay. Knocking down Caf1 or overexpressing a Caf1 catalytically inactive mutant impairs deadenylation and mRNA decay. P-bodies are not detected when deadenylation is blocked and are restored when the blockage is released. When deadenylation is impaired, P-body formation is not restorable, even when mRNAs exit the translating pool. These results support a dynamic interplay among deadenylation, mRNP remodeling, and P-body formation in selective decay of mammalian mRNA.
Zheng
Dinghai
D
Department of Biochemistry and Molecular Biology, The University of Texas Medical School, Houston, TX 77030, USA.
Ezzeddine
Nader
N
Chen
Chyi-Ying A
CY
Zhu
Wenmiao
W
He
Xiangwei
X
Shyu
Ann-Bin
AB
D000818:Animals; D022083:Cytoplasmic Structures / Q000187:drug effects / Q000378:metabolism*; D005095:Exoribonucleases; D006801:Humans; D051379:Mice; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000378:metabolism; D041681:NIH 3T3 Cells; D011061:Poly A / Q000378:metabolism; D026723:Polyadenylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D011506:Proteins / Q000378:metabolism; D011691:Puromycin / Q000494:pharmacology; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D054398:Receptors, CCR4 / Q000378:metabolism; D012097:Repressor Proteins; D012260:Ribonucleases
C515355:Ccr4 protein, mouse; D046912:Multiprotein Complexes; D011506:Proteins; D012333:RNA, Messenger; D054398:Receptors, CCR4; D012097:Repressor Proteins; D011061:Poly A; D011691:Puromycin; C489778:Cnot7 protein, mouse; D005095:Exoribonucleases; D012260:Ribonucleases