Comparative analyses of vertebrate CPEB proteins define two subfamilies with coordinated yet distinct functions in post-transcriptional gene regulation.

Background: Vertebrate CPEB proteins bind mRNAs at cytoplasmic polyadenylation elements (CPEs) in their 3' UTRs, leading to cytoplasmic changes in their poly(A) tail lengths; this can promote translational repression or activation of the mRNA. However, neither the regulation nor the mechanisms of action of the CPEB family per se have been systematically addressed to date.

Results: Based on a comparative analysis of the four vertebrate CPEBs, we determine their differential regulation by phosphorylation, the composition and properties of their supramolecular assemblies, and their target mRNAs.

Macrophage inflammation resolution requires CPEB4-directed offsetting of mRNA degradation.

Chronic inflammation is a major cause of disease. Inflammation resolution is in part directed by the differential stability of mRNAs encoding pro-inflammatory and anti-inflammatory factors. In particular, tristetraprolin (TTP)-directed mRNA deadenylation destabilizes AU-rich element (ARE)-containing mRNAs.

mRNA spindle localization and mitotic translational regulation by CPEB1 and CPEB4.

Transition through cell cycle phases requires temporal and spatial regulation of gene expression to ensure accurate chromosome duplication and segregation. This regulation involves dynamic reprogramming of gene expression at multiple transcriptional and posttranscriptional levels. In transcriptionally silent oocytes, the CPEB-family of RNAbinding proteins coordinates temporal and spatial translation regulation of stored maternal mRNAs to drive meiotic progression.

Author Correction: Musashi 1 regulates the timing and extent of meiotic mRNA translational activation by promoting the use of specific CPEs.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Musashi 1 regulates the timing and extent of meiotic mRNA translational activation by promoting the use of specific CPEs.

The translational reactivation of maternal mRNAs encoding meiotic drivers in vertebrates is accomplished mainly by cytoplasmic polyadenylation. The cytoplasmic polyadenylation elements (CPEs) present in the 3' untranslated regions (3' UTRs) of these transcripts, together with their cognate CPE-binding proteins (CPEBs), define a combinatorial code that determines the timing and extent of translational activation upon meiosis resumption. In addition, the RNA-binding protein Musashi1 (Msi1) regulates polyadenylation of CPE-containing mRNAs by a yet undefined CPEB-dependent or CPEB-independent mechanism.

Global Analysis of CPEBs Reveals Sequential and Non-Redundant Functions in Mitotic Cell Cycle.

CPEB (Cytoplasmic Polyadenylation Element Binding) proteins are a family of four RNA-binding proteins that regulate the translation of maternal mRNAs controlling meiotic cell cycle progression. But CPEBs are not limited to the transcriptionally silent germline; they are also expressed, in various combinations, in somatic cells, yet their role in regulation of mitosis-related gene expression is largely unknown. Deregulation of CPEB1 and CPEB4 have been linked to tumor development.

On the nature of DNA hyperchromic effect.

A combined theoretical-experimental study of the hyperchromic effect as occurring in the denaturation of a double stranded polyA-polyT is presented. Our theoretical/computational procedure allows us to reproduce the essential features of the experimental spectra and to characterize those molecular interactions responsible for the changes in the UV absorbance. We found that although excitonic intrastrand interactions strongly affect the absorbance, they are almost fully maintained in the single-stranded DNA.

Impact of methylation on the physical properties of DNA.

There is increasing evidence for the presence of an alternative code imprinted in the genome that might contribute to gene expression regulation through an indirect reading mechanism. In mammals, components of this coarse-grained regulatory mechanism include chromatin structure and epigenetic signatures, where d(CpG) nucleotide steps are key players. We report a comprehensive experimental and theoretical study of d(CpG) steps that provides a detailed description of their physical characteristics and the impact of cytosine methylation on these properties.

A relaxed specificity in interchain disulfide bond formation characterizes the assembly of a low-molecular-weight glutenin subunit in the endoplasmic reticulum.

Wheat (Triticum spp.) grains contain large protein polymers constituted by two main classes of polypeptides: the high-molecular-weight glutenin subunits and the low-molecular-weight glutenin subunits (LMW-GS). These polymers are among the largest protein molecules known in nature and are the main determinants of the superior technological properties of wheat flours.