Our understanding of the molecular mechanisms governing the development of the brain has been facilitated by genetic approaches in human and mouse that have identified several genes and protein products required for neocortical development and neuronal migration. The first identified neuronal migration gene was LIS1. Heterozygous loss-of-function of LIS1 resulted in the severe neuronal migration defect lissencephaly, or smooth brain. Recent studies by others and us have identified some important interactions that define at least some of the cellular function of LIS1. For example, LIS1 and the NudE homologue NDEL1 (coded by the Ndel1 gene, formerly NudE1) together bind the cytoplasmic dynein heavy chain (CDHC) to regulate dynein motor function. NDEL is phosphorylated by Cdk5/p35, suggesting that the activity of the LIS1/NDEL1/CDHC complex is regulated by phosphorylation. Cdk5-phosphorylated NDEL1 (P- NDEL1) binds to 14-3-3E, a member of a large family of binding proteins that regulate stability and subcellular localization of phosphoproteins, to protect P-NDEL1 from phosphatase attack. In this resubmission, we will focus our studies on the role of NDEL1 in the LIS1/NDEL1/CDHC complex because of its apparent central role in coordinating the function of LIS1 and cytoplasmic dynein These studies will provide further insight into neuronal migration and neocortical development by providing a more comprehensive understanding of the molecular intricacies that govern neocortical development, and will also provide insight into human lissencephaly. Therefore, we propose to investigate the function of NDEL1 in integrating these pathways in vivo by the following Specific Aims:
Aim 1. Test the hypothesis that NDEL1 has several important functions during brain development and in the adult by examining the dosage dependent effects of NDEL1 during neurogenesis, neuronal migration, cell survival and adult neuronal function in vivo. Based on our published and preliminary data after loss of LIS1, we predict that NDEL1 is critical for processes at all stages of brain development, and even in the postmitotic adult brain, although not in non-neuronal somatic tissues.
Aim 2. Test the hypothesis that the phosphorylation of NDEL1 by Cdk5/p35 and binding to 14-3-3e are critical for neuronal development and migration in vivo by producing specific Cdk5 phosphorylation site mutants in mice by BAG transgenesis.
Aim 3. Test the hypothesis that NDEL1 binding to LIS1 and CDHC regulates the function of dynein, and this binding is responsible for the in vivo phenotypes of mice with mutations in the LIS1/NUDEL/CDHC complex by producing Ndell alleles defective in binding for LIS1 and CDHC. ? ? ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
2R01NS041030-05
Application #
7049888
Study Section
Neurogenesis and Cell Fate Study Section (NCF)
Program Officer
Riddle, Robert D
Project Start
2000-12-01
Project End
2010-01-31
Budget Start
2006-02-01
Budget End
2007-01-31
Support Year
5
Fiscal Year
2006
Total Cost
$347,156
Indirect Cost
Name
University of California San Diego
Department
Pediatrics
Type
Schools of Medicine
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Moon, Hyang Mi; Youn, Yong Ha; Pemble, Hayley et al. (2014) LIS1 controls mitosis and mitotic spindle organization via the LIS1-NDEL1-dynein complex. Hum Mol Genet 23:449-66
Toba, Shiori; Tamura, Yasuhisa; Kumamoto, Kanako et al. (2013) Post-natal treatment by a blood-brain-barrier permeable calpain inhibitor, SNJ1945 rescued defective function in lissencephaly. Sci Rep 3:1224
Moon, Hyang Mi; Wynshaw-Boris, Anthony (2013) Cytoskeleton in action: lissencephaly, a neuronal migration disorder. Wiley Interdiscip Rev Dev Biol 2:229-45
Takitoh, Takako; Kumamoto, Kanako; Wang, Chen-Chi et al. (2012) Activation of Aurora-A is essential for neuronal migration via modulation of microtubule organization. J Neurosci 32:11050-66
Toba, Shiori; Hirotsune, Shinji (2012) A unique role of dynein and nud family proteins in corticogenesis. Neuropathology 32:432-9
Yamada, Masami; Hirotsune, Shinji; Wynshaw-Boris, Anthony (2010) The essential role of LIS1, NDEL1 and Aurora-A in polarity formation and microtubule organization during neurogensis. Cell Adh Migr 4:180-4
Wynshaw-Boris, Anthony; Pramparo, Tiziano; Youn, Yong Ha et al. (2010) Lissencephaly: mechanistic insights from animal models and potential therapeutic strategies. Semin Cell Dev Biol 21:823-30
Yamada, Masami; Hirotsune, Shinji; Wynshaw-Boris, Anthony (2010) A novel strategy for therapeutic intervention for the genetic disease: preventing proteolytic cleavage using small chemical compound. Int J Biochem Cell Biol 42:1401-7
Pramparo, Tiziano; Youn, Yong Ha; Yingling, Jessica et al. (2010) Novel embryonic neuronal migration and proliferation defects in Dcx mutant mice are exacerbated by Lis1 reduction. J Neurosci 30:3002-12
Yamada, Masami; Toba, Shiori; Takitoh, Takako et al. (2010) mNUDC is required for plus-end-directed transport of cytoplasmic dynein and dynactins by kinesin-1. EMBO J 29:517-31

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