The translational regulator CPEB1 provides a link between dcp1 bodies and stress granules.
The cytoplasmic polyadenylation element-binding protein (CPEB) has been characterized in Xenopus laevis as a translational regulator. During the early development, it behaves first as an inhibitor and later as an activator of translation. In mammals, its closest homologue is CPEB1 for which two isoforms, short and long, have been described. Here we describe an additional isoform with a different RNA recognition motif, which is differentially expressed in the brain and ovary. We show that all CPEB1 isoforms are found associated with two previously described cytoplasmic structures, stress granules and dcp1 bodies. This association requires the RNA binding ability of the protein, whereas the Aurora A phosphorylation site is dispensable. Interestingly, the rck/p54 DEAD box protein, which is known as a CPEB partner in Xenopus and clam, and as a component of dcp1 bodies in mammals, is also present in stress granules. Both stress granules and dcp1 bodies are involved in mRNA storage and/or degradation, although so far no link has been made between the two, in terms of neither morphology nor protein content. Here we show that transient CPEB1 expression induces the assembly of stress granules, which in turn recruit dcp1 bodies. This dynamic connection between the two structures sheds new light on the compartmentalization of mRNA metabolism in the cytoplasm.
Wilczynska
A
A
CNRS UPR1983, Institut André Lwoff, 7 rue Guy Moquet, 94801 Villejuif CEDEX, France.
Aigueperse
C
C
Kress
M
M
Dautry
F
F
Weil
D
D
D017398:Alternative Splicing; D020816:Amino Acid Motifs; D000818:Animals; D064127:Aurora Kinases; D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry; D003593:Cytoplasm / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000378:metabolism; D053487:DEAD-box RNA Helicases; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism*; D005260:Female; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010053:Ovary / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D014176:Protein Biosynthesis; D020033:Protein Isoforms; D011494:Protein Kinases / Q000737:chemistry; D017346:Protein Serine-Threonine Kinases; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012316:RNA Nucleotidyltransferases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D013997:Time Factors; D014157:Transcription Factors / Q000502:physiology*; D014162:Transfection; D014981:Xenopus; D029867:Xenopus Proteins / Q000737:chemistry; D039221:mRNA Cleavage and Polyadenylation Factors / Q000502:physiology*
C490386:CPEB1 protein, human; D018797:Cell Cycle Proteins; D020033:Protein Isoforms; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D029867:Xenopus Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; D049452:Green Fluorescent Proteins; D012313:RNA; D011494:Protein Kinases; C112134:AURKA protein, Xenopus; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D012316:RNA Nucleotidyltransferases; D010450:Endopeptidases; C020071:dipeptidyl carboxypeptidase; C094683:DDX6 protein, human; D053487:DEAD-box RNA Helicases; D010100:Oxygen