Oligomerization of EDEN‐BP is required for specific mRNA deadenylation and binding

Abstract

Background information. mRNA deadenylation [shortening of the poly(A) tail] is often triggered by specific sequence elements present within mRNA 3 untranslated regions and generally causes rapid degradation of the mRNA. In vertebrates, many of these deadenylation elements are called AREs (AU-rich elements). The EDEN (embryo deadenylation element) sequence is a Xenopus class III ARE. EDEN acts by binding a specific factor, EDEN-BP (EDEN-binding protein), which in turn stimulates deadenylation.Results. We show here that EDEN-BP is able to oligomerize. A 27-amino-acid region of EDEN-BP was identified as a key domain for oligomerization. A mutant of EDEN-BP lacking this region was unable to oligomerize, and a peptide corresponding to this region competitively inhibited the oligomerization of full-length EDEN-BP. Impairing oligomerization by either of these two methods specifically abolished EDEN-dependent deadenylation. Furthermore, impairing oligomerization inhibited the binding of EDEN-BP to its target RNA, demonstrating a strong coupling between EDEN-BP oligomerization and RNA binding.Conclusions. These data, showing that the oligomerization of EDEN-BP is required for binding of the protein on its target RNA and for EDEN-dependent deadenylation in Xenopus embryos, will be important for the identification of cofactors required for the deadenylation process.

CUG-BP and 3'UTR sequences influence PARN-mediated deadenylation in mammalian cell extracts

“…We hypothesize that the cFos ΔB, ΔC and ΔE deletion variants may juxtapose UGUR sites in the RNA substrate and create a more efficient CUG-BP binding region that results in more effective UV cross-linking and faster deadenylation kinetics. This model is consistent with the recent observation by Cosson et al (2006) that oligomerization of the CUG-BP homolog EDEN-BP is required for efficient RNA binding and deadenylation in Xenopus.…”

Celf1 regulation of dmrt2a is required for somite symmetry and left-right patterning during zebrafish development

“…Either 50 or 150 pg celf1 mRNA was injected into one-cell-stage zebrafish embryos; as a control, either 50 or 150 pg mRFP mRNA was injected. Because a deletion mutant of the linker domain of human or frog Celf1 (Celf1 linker ) is known to lose its functional activity by losing RNA-binding activity or by preventing oligomerization (Takahashi et al, 2000;Cosson et al, 2006), we used zebrafish celf1 linker as a negative control in this study. To confirm its protein expression in embryos, we injected 50 pg celf1 linker mRNA into one-cell-stage zebrafish embryos, and found that a 26 kDa protein, equivalent to that of mutant protein, was expressed in the manipulated embryos (supplementary material Fig.…”

CELF1, a Multifunctional Regulator of Posttranscriptional Networks

“…The Zebrafish protein Brul, a homologue of EDEN-BP with 81% identity, was also shown to preferentially bind to GU-rich RNAs [63]. EDEN-BP and Bru-3 can bind to GRE-RNA as dimers [64], [65] and may require GU-rich sequences of sufficient length to allow dimer formation [66]. In addition to the primary GU-rich sequence, adjacent sequence elements may also be important for assembly of CELF proteins on RNA by allowing optimal secondary structure to facilitate the formation of RNA-protein complexes [67], [68].…”

“…The divergent domain may also facilitate CELF:CELF homotypic interactions [64] which may influence its activity. For example, CELF:CELF interactions appear to activate RNA deadenylation in Xenopus extracts [66].…”