Cross talk between spliceosome and microprocessor defines the fate of pre-mRNA.
The spliceosome and the microprocessor complex (MPC) are two important processing machineries that act on precursor (pre)-mRNA. Both cleave the pre-mRNA to generate spliced mature transcripts and microRNAs (miRNAs), respectively. While spliceosomes identify in a complex manner correct splice sites, MPCs typically target RNA hairpins (pri-miRNA hairpins). In addition, pre-mRNA transcripts can contain pri-miRNA-like hairpins that are cleaved by the MPC without generating miRNAs. Recent evidence indicates that the position of hairpins on pre-mRNA, their distance from splice sites, and the relative efficiency of cropping and splicing contribute to determine the fate of a pre-mRNA. Depending on these factors, a pre-mRNA can be preferentially used to generate a miRNA, a constitutively or even an alternative spliced transcript. For example, competition between splicing and cropping on splice-site-overlapping miRNAs (SO miRNAs) results in alternative spliced isoforms and influences miRNA biogenesis. In several cases, the outcome of a pre-mRNA transcript and its final handling as miRNA or mRNA substrate can be frequently closely connected to the functional relationships between diverse pre-mRNA processing events. These events are influenced by both gene context and physiopathological conditions.
Human Molecular Genetics, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
Chiara
C
Mattioli
Giulia
G
Pianigiani
Franco
F
Pagani
D017398:Alternative Splicing / Q000235:genetics; D006801:Humans; D055029:Inverted Repeat Sequences / Q000235:genetics; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D012322:RNA Precursors / Q000235:genetics* / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012326:RNA Splicing / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics*; D017381:Spliceosomes / Q000235:genetics* / Q000378:metabolism
D035683:MicroRNAs; D020033:Protein Isoforms; D012322:RNA Precursors; D012333:RNA, Messenger