Alternative pre-mRNA splicing affects the expression of gene products involved in many aspects of cell growth and differentiation, yet the mechanisms by which it is regulated are only beginning to be elucidated. SR proteins and related factors are thought to play important roles in the regulation of splicing. These factors form regulatory complexes at sites internal to the exons of alternatively spliced pre-mRNAs and function to recruit factors from the general splicing machinery to nearby splice sites that otherwise would not be recognized. Although SR proteins are highly phosphorylated, the role of phosphorylation in the regulation of splicing is largely unknown. We propose to investigate how SR protein phosphorylation affects the assembly and function of sex-specific regulatory complexes formed on a splicing enhancer in the doublesex pre-mRNA. Preliminary studies indicate that the LAMMER kinase Darkener-of- apricot phosphorylates SR proteins and is required for normal regulation of doublesex RNA splicing. We will test whether the phosphorylation of proteins from the doublesex splicing enhancer complex affects the ability of SR proteins, and related regulatory factors such as TRA and TRA2, to interact with each other and with the pre-mRNA. Other experiments will compare the effects of different classes of kinases on SR protein function. Finally, we will produce strains of Drosophila with mutations in SR protein kinases to examine their roles in development and on the phosphorylation of specific SR proteins in vivo. We anticipate that these studies will provide significant new insights into the mechanisms by which splicing is regulated and will open up new avenues for future studies on phosphorylation of SR proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM058625-04
Application #
6490251
Study Section
Molecular Biology Study Section (MBY)
Program Officer
Rhoades, Marcus M
Project Start
1999-01-01
Project End
2003-12-31
Budget Start
2002-01-01
Budget End
2003-12-31
Support Year
4
Fiscal Year
2002
Total Cost
$215,601
Indirect Cost
Name
University of Texas MD Anderson Cancer Center
Department
Genetics
Type
Other Domestic Higher Education
DUNS #
001910777
City
Houston
State
TX
Country
United States
Zip Code
77030
Xu, Dong-Qing; Mattox, William (2006) Identification of a splicing enhancer in MLH1 using COMPARE, a new assay for determination of relative RNA splicing efficiencies. Hum Mol Genet 15:329-36
Unni, Emmanual; Su, Shihuang; Mattox, William (2003) Analysis of a null mutation in the Drosophila splicing regulator Tra2 suggests its function is restricted to sexual differentiation. Genesis 37:76-83
Chandler, Dawn S; Qi, Junlin; Mattox, William (2003) Direct repression of splicing by transformer-2. Mol Cell Biol 23:5174-85
Chandler, D S; McGuffin, M E; Mattox, W (2001) Functionally antagonistic sequences are required for normal autoregulation of Drosophila tra-2 pre-mRNA splicing. Nucleic Acids Res 29:3012-9