The research suggested the necessary existence of a number of biological processes and active entities, many of which have since been tracked down by other scientists. Some, however, have resisted intensive inquiry. Now, researchers at The Wistar Institute and colleagues have resolved one of the important biological questions to which this earlier research pointed. A report on their findings appears in the October 21 issue of Cell.
Researchers who followed Roberts and Sharp discovered a molecular machine called a spliceosome, which was responsible for processing messenger RNA, or mRNA, the gene transcript from which proteins are produced. The spliceosome does this by snipping out the introns from the mRNA and then stitching together the exons into the finished mRNA. The activity takes place in the nucleus of the cell.
The spliceosome itself is composed of proteins and so-called small nuclear RNAs, or snRNAs. These snRNAs, as is the case with other forms of non-coding RNA in the nucleus, never produce proteins but play important roles in facilitating and regulating genetic activity. How these snRNAs were processed, however, remained a mystery for over twenty years. And because the spliceosome underlies the successful transcription of every single gene in the body, the question has been a vital one to answer.
In the new study, the Wistar-led research team identifies an entirely novel multi-protein complex called the Integrator that plays a central role in the processing of snRNAs. The Integrator appears to perform two important duties simultaneously. It binds a molecule called CTD, which is a component of the polym
Contact: Franklin Hoke
The Wistar Institute