Die Funktion einer hirnspezifischen nicht-messenger RNA bei der Regulation der Prozessierung des 5-HT2C Serotonin-Rezeptors
Zusammenfassung der Projektergebnisse
The project centered around a small nucleolar RNA, (snoRNA), HBII-52. This RNA is expressed from the SNURF-SNRPN locus in the 15q11-q13 region. Loss of gene expression from this region causes Prader-Willi syndrome, the most frequent genetic cause for type II diabetes. We could confirm our working hypothesis that HBII-52 regulates alternative splicing of pre-mRNAs. We identified 13 pre-mRNAs that show a change in splicing patterns when the snoRNA HBII-52 is expressed ectopicaliy. We concentrated on five new pre-mRNA targets that showed a consistant dependency on snoRNA expression in three different systems: (i) the splicing of the endogenous genes changes after ectopicaliy expressing HBII-52; (ii) reporter gene constructs alter their splicing pattern after snoRNA expression and (iii) differences in splicing are seen when brain RNA from wild-type and MBII-52 knock out animals is compared. We could also clarify the mechanism of snoRNA action, which was the most surprising outcome of the project. It was previously reported that the SNURF-SNRPN locus gives only rise to "full-length", traditional snoRNAs. Using RNAse protection analysis, we could show that the mouse ortholog of the human HBII-52 snoRNA, called MBII-52, is processed into smaller RNAs that we describe for the first time. We call these novel RNAs psnoRNAs for processed snoRNAs. The existance of processed snoRNAs (psnoRNAs) explains the influence of MBII-52 on splice site selection. We demonstrate that psnoRNAs associate with hnRNPs, not the canonical C/D-box snoRNA assciated proteins. We hypothezise that psnoRNAs work similar to bifunctional oligonucleotides. It is likely that the loss of these psnoRNAs and the loss of the ability to properly regualte splice site selection in neurons is the molecular cause for Prader Willi syndrome. In summary, we identified a new class of RNAs, processed snoRNAs (psnoRNAs) that regualte splice site selection. Loss of these RNAs is the most likely cause for Prader Willi syndrome.
Projektbezogene Publikationen (Auswahl)
- (2008). Rapid generation of splicing reporters with pSpliceExpress. Gene 427, 104-110
Kishore, S., Khanna, A., and Stamm, S.
- (2008). Substances that can change alternative splice-site selection. Biochem Soc Trans 36, 483-490
Sumanasekera, C., Watt, D. S., and Stamm, S.
- (2009). Role of alternative splicing of the Serotonin Receptor 2C in the Prader-Willi syndrome. In: The Pathophysiology of Central 5-HT2C Receptors, G. Di Giovanni, ed.
Kishore, S., and Stamm, S.
