Pre-mRNA splicing of Pol II transcripts is executed in the mammalian cell nucleus within a huge (21 MDa) and highly dynamic RNP machine - the supraspliceosome. It is composed of four splicing active native spliceosomes, each resembling an in vitro assembled spliceosome, which are connected by the pre-mRNA. Supraspliceosomes harbor protein splicing factors and all the five-spliceosomal U snRNPs....

W hen it was first discovered, RNA was thought to have just one job in the cell: that of a messenger carrying the genetic instructions for protein synthesis to the ribosomes. But, since then, different RNA species have been shown to be key to the construction (1) and function of the ribosomal machinery and to control both the spliced state and levels of messenger RNAs (2–4). Right from the star...

In RNA silencing, microRNA (miRNA)-mediated translational repression occurs through mechanisms that do not invoke messenger-RNA (mRNA) target cleavage by Argonaute proteins. The nature of these mechanisms is unclear, but several recent studies have proposed that a direct interaction between the mRNA–cap and the middle (MID) domain of Argonautes is involved. Here, we present crystallographic and...

Myotonic dystrophy (DM), the most common form of muscular dystrophy in adult humans, results from expansion of a CTG repeat in the 3' untranslated region of the DMPK gene. The mutant DMPK messenger RNA (mRNA) contains an expanded CUG repeat and is retained in the nucleus. We have expressed an untranslated CUG repeat in an unrelated mRNA in transgenic mice. Mice that expressed expanded CUG repea...

Messenger RNA (mRNA) molecules are transcribed in the nucleus and then undergo export into the cytoplasm, where they are translated to produce proteins. Some mRNA transcripts do not immediately undergo translation but, instead, are directed to specific areas for local translation or distribution. This produces an asymmetric distribution of cytoplasmic proteins, providing localized activities in...

RNA-binding proteins (RBPs) are essential for regulating RNA metabolism, stability, and translation within cells. Recent studies have shown that RBPs not restricted to intracellular functions can be found in extracellular vesicles (EVs) different mammalian EVs released by fungi contain a variety of involved metabolism. These include helicases, which play roles synthesis, folding, degradation. A...

Genetic information is stored in living organisms in DNA, RNA and protein molecules. The primary structure of these molecules is a linear chain, and hence they can be viewed as sequences of letters. This sequential biological information can be transferred between DNA, RNA and protein molecules. The so-called “central dogma of molecular biology” describes which types of transfers are allowed: i...

African trypanosomes cause a parasitic disease known as sleeping sickness. Mitochondrial transcript maturation in these organisms requires a RNA editing reaction that is characterized by the insertion and deletion of U-nucleotides into otherwise non-functional mRNAs. Editing represents an ideal target for a parasite-specific therapeutic intervention since the reaction cycle is absent in the inf...

BACKGROUND During pre-mRNA splicing, dynamic rearrangement of RNA secondary structure within the spliceosome is crucial for intron recognition and formation of the catalytic core. Splicing factors belonging to the DExD/DExH-box family of RNA-dependent ATPases are thought to have a central role in directing these rearrangements by unwinding RNA helices. Proof of this hypothesis has, however, bee...