Right in the middle of the central dogma sits the RNA world, through which the information in DNA passes to create the functional state of the cell. This world is rife with nonprotein enzymes, mystery machines and unfathomed regulatory sophistication. Among its wonders are the ribosome, the spliceosome, catalytic RNAs, small transregulatory RNAs such as microRNAs and CRISPRs, large noncoding RNAs, riboswitches and RNA helicases. In the annual meeting thematic group “RNA: from Catalysis to Regulation,” we will explore the surface of this world in four parts.
The elusive spliceosome
Eukaryotic genes are split such that the interpretation of what information should go into the mRNA is left to the spliceosome, a bevy of complexes that bind, arrange and splice exons together. The coordinated transitions from one complex to the next are so dynamic that structural analysis requires tricks to freeze the spliceosome in its tracks.
The first session, “The Spliceosome: Fitting the Pieces Together,” will focus on this mystery. First up will be Soo-Chen Cheng (Academia Sinica in Taipei), who will relate spliceosome dynamics to function in either of the two reversible catalytic steps carried out by the yeast spliceosome.
How spliceosome function is influenced by the ongoing transcription that creates its substrate will be addressed by Tracy L. Johnson (University of California, San Diego), who will describe studies of co-transcriptional splicing and spliceosome dynamics.
Finally, Melissa S. Jurica (University of California, Santa Cruz) will describe key changes in protein composition and complex structure that accompany human spliceosome transitions in vitro.
Fate as a matter of folding
Some rules for RNA folding are simple: G pairs with C or U, and A pairs with U. These rules (plus stacking) generate an RNA-folding landscape that can include many stable solutions. The next layer is more obscure, with tertiary interactions and helical packing interactions that create the functional shape.
The second session, “RNA Dynamics: Function Follows Folding,” will explore how these interactions affect the function of RNA elements.