Tissue specific alternative splicing plays a prominent role in regulating gene expression in metazoans. Although the molecular events required to splice a simple pre-mRNA in vitro are fairly well understood, we remain largely ignorant of how the complex process of splicing is regulated in vivo. An understanding of how this process works is of fundamental importance since errors in RNA splicing are associated with a variety of human diseases, including cancer. The long-term goal of this project is to understand regulation by exon skipping, one of the most common forms of alternative splicing in humans. Specifically, we study the splicing regulation of the Drosophila developmental switch gene Sex-lethal (Sxl). Based on our earlier studies, we propose a novel mechanism by which the female specific product of the Sxl gene controls its own splicing pattern by interacting with, and inactivating, core components of the spliceosome. As outlined in the proposal, we are continuing to exploit Drosophila genetics to identify and delineate the function of proteins that participate in this biologically important example of splicing regulation. We are also using biochemical approaches to test the models that are known to be compatible with what we observe in vivo. Lastly, we are investigating, for the first time, whether the mechanism utilized to control Sxl is tissue-, as well as sex-specific. The combined data from these studies will provide insights into the complexities associated with splicing regulation that simply cannot be obtained via studies carried out solely in tissue culture cells. Due to the remarkable conservation of the splicing machinery from humans to flies, the paradigms we develop using the very tractable Drosophila system are relevant to human biology. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM061039-06
Application #
7497587
Study Section
Development - 2 Study Section (DEV2)
Program Officer
Bender, Michael T
Project Start
2002-05-01
Project End
2011-07-31
Budget Start
2008-08-01
Budget End
2009-07-31
Support Year
6
Fiscal Year
2008
Total Cost
$309,000
Indirect Cost
Name
Case Western Reserve University
Department
Genetics
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Salz, Helen K (2013) Sex, stem cells and tumors in the Drosophila ovary. Fly (Austin) 7:3-7
Chau, Johnnie; Kulnane, Laura Shapiro; Salz, Helen K (2012) Sex-lethal enables germline stem cell differentiation by down-regulating Nanos protein levels during Drosophila oogenesis. Proc Natl Acad Sci U S A 109:9465-70
Salz, Helen K (2011) Sex determination in insects: a binary decision based on alternative splicing. Curr Opin Genet Dev 21:395-400
Johnson, Matthew L; Nagengast, Alexis A; Salz, Helen K (2010) PPS, a large multidomain protein, functions with sex-lethal to regulate alternative splicing in Drosophila. PLoS Genet 6:e1000872
Salz, Helen K; Erickson, James W (2010) Sex determination in Drosophila: The view from the top. Fly (Austin) 4:60-70
Chau, Johnnie; Kulnane, Laura Shapiro; Salz, Helen K (2009) Sex-lethal facilitates the transition from germline stem cell to committed daughter cell in the Drosophila ovary. Genetics 182:121-32
Penn, Jill K M; Graham, Patricia; Deshpande, Girish et al. (2008) Functioning of the Drosophila Wilms'-tumor-1-associated protein homolog, Fl(2)d, in Sex-lethal-dependent alternative splicing. Genetics 178:737-48
Chaouki, Ahmad Sami; Salz, Helen K (2006) Drosophila SPF45: a bifunctional protein with roles in both splicing and DNA repair. PLoS Genet 2:e178
Salz, Helen K; Mancebo, Ricardo S Y; Nagengast, Alexis A et al. (2004) The Drosophila U1-70K protein is required for viability, but its arginine-rich domain is dispensable. Genetics 168:2059-65
Nagengast, Alexis A; Stitzinger, Shane M; Tseng, Chin-Hsiu et al. (2003) Sex-lethal splicing autoregulation in vivo: interactions between SEX-LETHAL, the U1 snRNP and U2AF underlie male exon skipping. Development 130:463-71