The aim of this project is to characterize the function of Down syndrome critical region 1 (DSCR1) that is overexpressed in the brain of Down syndrome fetus. It belongs to a family of highly conserved proteins that bind and inhibit calcineurin, a phosphatase important for learning and memory, but its functional significance remains unclear. To investigate its physiological role, we generated a Drosophila mutant of nebula, an ortholog of human DSCR1. In this project we show that the nebula mutant shows enhanced calcineurin, but reduced PKA activities, and decreased level of phosphorylated cyclic AMP responsive element binding (CREB) protein. The nebula mutant also exhibits defective olfactory learning and long-term memory, while short-term memory remains intact. These results suggest that DSCR1 is required for learning and memory and that alteration of DSCR1 expression in the brain could be one of the possible underlying mechanisms of mental retardation in Down syndrome.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Intramural Research (Z01)
Project #
1Z01NS002988-02
Application #
6548734
Study Section
(NGB)
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
2001
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Chang, Karen T; Min, Kyung-Tai (2005) Drosophila melanogaster homolog of Down syndrome critical region 1 is critical for mitochondrial function. Nat Neurosci 8:1577-85
Taylor, J Paul; Taye, Addis A; Campbell, Catherine et al. (2003) Aberrant histone acetylation, altered transcription, and retinal degeneration in a Drosophila model of polyglutamine disease are rescued by CREB-binding protein. Genes Dev 17:1463-8
Chang, Karen T; Shi, Yi-Jun; Min, Kyung-Tai (2003) The Drosophila homolog of Down's syndrome critical region 1 gene regulates learning: implications for mental retardation. Proc Natl Acad Sci U S A 100:15794-9
Kang, Hyung-Lyun; Benzer, Seymour; Min, Kyung-Tai (2002) Life extension in Drosophila by feeding a drug. Proc Natl Acad Sci U S A 99:838-43
Chang, Karen T; Min, Kyung-Tai (2002) Regulation of lifespan by histone deacetylase. Ageing Res Rev 1:313-26