#spliceosome

The RNA that snips and stitches RNA

RNA is a fundamental molecule that codes for protein and controls gene expression, playing a part in regulating many cell responses and vital processes. The genetic information contained in premature messenger RNA (mRNA), before being converted to proteins, needs to be processed and cleared of its non-coding sections, known as introns. In several simpler organisms, this key process is carried out by group II introns, enzymes entirely made up of RNA (different from the true protein enzymes) called ribozymes that are able to self-cleave by removing themselves from the mRNA filament and thereby promoting RNA maturation.

A SISSA/CNR-IOM Democritos study carried out in collaboration with the École Polytechnique Fédérale de Lausanne (EPFL) gives a detailed account of the cleavage reaction, so far totally unknown. The mechanism is thought to be similar to that of the human spliceosome whose malfunctioning can lead to several diseases among which neurodegeneration and cancer. The study has been published in the Journal of the American Chemical Society.

Lorenzo Casalino, Giulia Palermo, Ursula Rothlisberger, Alessandra Magistrato. Who Activates the Nucleophile in Ribozyme Catalysis? An Answer from the Splicing Mechanism of Group II Introns. Journal of the American Chemical Society, 2016; DOI: 10.1021/jacs.6b01363

The Spliceosome: More Than Meets the Eye

Certain diseases such as cystic fibrosis and muscular dystrophy are linked to genetic mutations that damage the important biological process of rearranging gene sequences in pre-messenger RNA, a procedure called RNA splicing.

These conditions are difficult to prevent because scientists are still grasping to understand how the splicing process works. Now, researchers from Brandeis University and the University of Massachusetts Medical School have teamed up to unravel a major component in understanding the process of RNA splicing.

In a recent paper published in Cell Press, research specialist Inna Shcherbakova of Brandeis and UMMS, and a team of researchers led by professors Jeff Gelles (Brandeis) and Melissa J. Moore (UMMS), explain how the molecular machine known as the spliceosome begins the process of rearranging gene sequences.