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Mechanisms of pre-mRNA splicing: classical versus non-classical pathways
P.G. Zaphiropoulos
Department of Bioscience, Center for Nutrition and Toxicology,
Karolinska Institute, Novum, Sweden
Offprint requests to: Dr. Peter
G. Zaphiropoulos, Department of Bioscience, Center for Nutrition and Toxicology,
Karolinska Institute, Novum, 141 57, Huddinge, Sweden
Summary. Expression of genetic
information proceeds through two major biological events, transcription
and translation. However, in eukaryotic cells, the primary transcript (pre-mRNA)
is not the template that the translational apparatus scans through, in order
to produce the corresponding protein. Pre-mRNAs undergo several modifications
(cap site addition, poly A+ tail addition) prior to becoming mature mRNAs,
with the most important one being the excision (splicing) of the intronic
sequences. Yet, the mechanisms that regulate the splicing process and the
generation of alternatively spliced mRNA products are still poorly understood.
Moreover recent findings suggest that this process also has the capability
to produce an additional set of RNA products that differ from typical mRNA
molecules. In these novel RNA transcripts the order of the exons has been
changed relative to genomic DNA. Furthermore, the properties of these transcripts
suggest that they may represent circular RNA molecules. Histol Histopathol
13, 585-589 (1998)
Key words: Exon definition,
Exon juxtaposition, Trans-splicing, Circular RNAs, Scrambled exons
DOI: 10.14670/HH-13.585
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