TY - JOUR T1 - Lack of Huntingtin-Associated Protein-1 Causes Neuronal Death Resembling Hypothalamic Degeneration in Huntington's Disease JF - The Journal of Neuroscience JO - J. Neurosci. SP - 6956 LP - 6964 DO - 10.1523/JNEUROSCI.23-17-06956.2003 VL - 23 IS - 17 AU - Shi-Hua Li AU - Zhao-Xue Yu AU - Cui-Lin Li AU - Huu-Phuc Nguyen AU - Yong-Xing Zhou AU - Chuxia Deng AU - Xiao-Jiang Li Y1 - 2003/07/30 UR - http://www.jneurosci.org/content/23/17/6956.abstract N2 - Huntington's disease (HD) is caused by a polyglutamine expansion in the disease protein huntingtin. The polyglutamine expansion causes huntingtin to interact abnormally with a number of proteins. However, it is unclear whether, and how, huntingtin-associated proteins are involved in the neurodegeneration in HD. Here, we show that huntingtin-associated protein-1 (HAP1), which is involved in intracellular trafficking of epidermal growth factor receptor (EGFR), is highly expressed in the hypothalamus. Mice lacking HAP1 die after birth because of depressed feeding activity. Terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling staining and electron microscopic examination revealed the degeneration in hypothalamic regions that control feeding behavior. Hypothalamic degeneration was also observed in HD transgenic mice that have a significant loss of body weight. Inhibition of HAP1 expression decreases EGFR signaling and cell viability, whereas overexpression of HAP1 enhances this signaling activity and inhibits mutant huntingtin-mediated cytotoxicity. These results suggest that the effect of mutant huntingtin on HAP1 and EGFR signaling may contribute to the hypothalamic neurodegeneration and loss of body weight in HD. ER -