Genetic studies strongly indicate that the Prader-Willi syndrome is caused by the loss of small nucleolar RNAs (snoRNA). SnoRNAs are short RNAs that do not encode a protein. In most cases studied, snoRNAs help in the modification of other RNAs. However, the function of the snoRNAs missing in people with Prader-Willi syndrome is not clear. In published and preliminary data we showed that one of these snoRNAs, HBII-52, regulates pre-mRNA splicing of at least seven genes. Pre-mRNA splicing is the process that makes mature mRNAs out of their precursors. Most pre-mRNAs are alternatively spliced, as several different molecules are made from a single precursor molecule. mRNAs contain the information to produce proteins and the alternative splicing process allows genes to make different proteins from a single precursor pre-mRNA. Our findings indicate that the snoRNAs missing in Prader-Willi syndrome regulate which proteins are made from at least seven different genes. In a collaborative project, we propose to identify substances that regulate the splicing pattern of two pre-mRNAs that are regulated by a snoRNA missing in people with Prader-Willi syndrome. The two mRNAs, the serotonin receptor and corticotrophin releasing hormone receptor are potentially involved in the eating disorder and the central adrenal insufficiency observed in the Prader-Willi syndrome. We will use a recently established and working screening system to identify substances affecting alternative splicing in a similar manner as snoRNA. Most of the substances that we will be testing have FDA approval or are under FDA consideration. Several drugs are already known to act on distinct splicing regulatory proteins. We will therefore determine what other regulatory proteins could substitute for the loss of HBII-52, with the aim to test then drugs that have been shown to regulate these splicing factors in other systems. This work is relevant for the mission of FPWR, as it could identify drugs that modulate the function of genes that are important for the eating disorder and the central adrenal insufficiency observed in the Prader-Willi syndrome. These drugs could be further tested in cell and mouse models and could be a first step towards a therapy.
C/D-box snoRNAs form methylating and non-methylating ribonucleoprotein complexes: Old dogs show new tricks. Falaleeva M, Welden JR, Duncan MJ, Stamm S. 2017 Jun;39(6).
Dual function of C/D box snoRNAs in rRNA modification and alternative pre-mRNA splicing. Falaleeva M, Pages A, Matuszek Z, Hidmi S, Agranat-Tamir L, Korotkov K, Nevo Y, Eyras E, Sperling R, Stamm S. Proceedings of the National Academy of Sciences of the United States of America, 2016 Mar 22;113(12):E1625-34.
SNORD116 and SNORD115 change expression of multiple genes and modify each other's activity. Falaleeva M, Surface J, Shen M, de la Grange P, Stamm S. Gene, 2015 Nov 10;572(2):266-73.
Pyrvinium pamoate changes alternative splicing of the serotonin receptor 2C by influencing its RNA structure. Shen M, Bellaousov S, Hiller M, de La Grange P, Creamer TP, Malino O, Sperling R, Mathews DH, Stoilov P, Stamm S. Nucleic Acids Research. 2013 41(6):3819-3832.
Direct cloning of double-stranded RNAs from RNase protection analysis reveals processing patterns of C/D box snoRNAs and provides evidence for widespread antisense transcript expression. Shen M, Eyras E, Wu J, Khanna A, Josiah S, Rederstorff M, Zhang MQ, Stamm S. Nucleic Acids Research. 39:9720-30, 2011.
The snoRNA MBII-52 (SNORD 115) is processed into smaller RNAs and regulates alternative splicing. Kishore S, Khanna A, Zhang Z, Hui J, Balwierz PJ, Stefan M, Beach C, Nicholls RD, Zavolan M, Stamm S. Human Molecular Genetics 19:1153-64, 2010.
Rapid generation of splicing reporters with pSpliceExpress. Kishore S, Khanna A, Stamm S. Gene. 427(1-2):104-10, 2008.
Stefan Stamm, Ph.D.
University of Kentucky