The biosynthesis of mouse nerve growth factor, an important regulator of neuronal development will be examined by translation of hybrid selected NGF-mRNA and by transcription and translation of NGF-cDNA in a number of systems. The NGF precursor and the intermediates in the biosynthesis will be characterized by size and peptide composition and the mechanism of the processing by kallikrein enzymes explored. Radioimmune assays and single stranded probes will be used to determine if proteins analogous to the Alpha and Gamma subunits appear in sympathetic target tissues and to explore their synthesis. The corresponding proteins in the African rat submaxillary gland will be characterized. The mechanisms whereby nerve growth factor (NGF) induces and maintains the differentiated state of a clonal cell line of rat pheochromocytoma, PC12 will be studied. In order to approach the nature of the intracellular signals which direct this action the NGF receptors will be cloned by transfection of PC12 cell DNA into a mouse L cell recipient and selection of transfected cells expressing the receptor by cell sorting after binding of a suitable fluorescinated antibody to the receptor. The NGF receptors themselves will be purified from PC12 cells or from a transfected cell line expressing large numbers of receptors and compared by peptide mapping. The fate of the internalized NGF-NGF receptor will be followed by taking advantage of the differential trypsin sensitivity and molecular weights of the two forms. In PC12 cells NGF induces and maintains neurite formation. Removal of NGF or addition of microtubule depolymerizing drugs causes neurite disintegration. The mechanism by which NGF enhances microtubule stability will be explored by measurements of the levels of Alpha, Beta tubulin, tau and MAP1 proteins and of the specific mRNAs under various conditions and kinetics of neurite outgrowth.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Research Project (R01)
Project #
Application #
Study Section
Neurology B Subcommittee 1 (NEUB)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Stanford University
Schools of Medicine
United States
Zip Code
Liu, Ning; Varma, Sushama; Tsao, David et al. (2007) Depleting endogenous neurotrophin-3 enhances myelin formation in the Trembler-J mouse, a model of a peripheral neuropathy. J Neurosci Res 85:2863-9
Yamauchi, Junji; Chan, Jonah R; Miyamoto, Yuki et al. (2005) The neurotrophin-3 receptor TrkC directly phosphorylates and activates the nucleotide exchange factor Dbs to enhance Schwann cell migration. Proc Natl Acad Sci U S A 102:5198-203
Liu, Ning; Varma, Sushama; Shooter, Eric M et al. (2005) Enhancement of Schwann cell myelin formation by K252a in the Trembler-J mouse dorsal root ganglion explant culture. J Neurosci Res 79:310-7
Yamauchi, Junji; Miyamoto, Yuki; Tanoue, Akito et al. (2005) Ras activation of a Rac1 exchange factor, Tiam1, mediates neurotrophin-3-induced Schwann cell migration. Proc Natl Acad Sci U S A 102:14889-94
Chan, Jonah R; Watkins, Trent A; Cosgaya, Jose M et al. (2004) NGF controls axonal receptivity to myelination by Schwann cells or oligodendrocytes. Neuron 43:183-91
Liu, Ning; Yamauchi, Junji; Shooter, Eric M (2004) Recessive, but not dominant, mutations in peripheral myelin protein 22 gene show unique patterns of aggregation and intracellular trafficking. Neurobiol Dis 17:300-9
Yamauchi, Junji; Chan, Jonah R; Shooter, Eric M (2004) Neurotrophins regulate Schwann cell migration by activating divergent signaling pathways dependent on Rho GTPases. Proc Natl Acad Sci U S A 101:8774-9
Tolwani, Ravi J; Cosgaya, Jose M; Varma, Sushama et al. (2004) BDNF overexpression produces a long-term increase in myelin formation in the peripheral nervous system. J Neurosci Res 77:662-9
Cosgaya, Jose M; Chan, Jonah R; Shooter, Eric M (2002) The neurotrophin receptor p75NTR as a positive modulator of myelination. Science 298:1245-8
Ryan, Mary C; Shooter, Eric M; Notterpek, Lucia (2002) Aggresome formation in neuropathy models based on peripheral myelin protein 22 mutations. Neurobiol Dis 10:109-18

Showing the most recent 10 out of 103 publications