The long term goal of this project is to define the cellular mechanisms of dendritic transport, especially the mechanisms responsible for the selective dendritic transport of RNA. While the sorting and transport of mRNA are ubiquitous biological processes, they are of particular importance in neurons, where they are thought to contribute to the development and plasticity of postsynaptic sites. Previous studies have demonstrated that dendrites, but not axons, have the capacity for RNA transport and have defined some of the mRNAs that undergo dendritic transport. The present proposal focuses on three representative dendritic mRNAs, those that encode CAMII kinase, MAP2b, and Arc. Defective herpesvirus vectors will be used to express tagged constructs of these mRNAs in cultured rat hippocampal neurons in order to study their targeting and transport. One experiment will use deletion analysis to define a minimum targeting sequence that is sufficient to direct an exogenous message to the dendrites. The mechanisms that prevent most neuronal mRNAs from entering dendrites will also be examined. A second experiment will use in situ hybridization at different times after the expression of tagged constructs to define the rates of transport of CAMII kinase, MAP2b, and Arc mRNAs and to determine if their transport is regulated by neuronal activity. Selective inhibitors and antisense inhibition of motor protein expression will be used to test the hypothesis that dendritic mRNA transport is mediated by minus-end directed, microtubule-based motors.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
7R01NS023094-14
Application #
2735571
Study Section
Neurology B Subcommittee 2 (NEUB)
Program Officer
Baughman, Robert W
Project Start
1986-01-01
Project End
2000-06-30
Budget Start
1998-07-01
Budget End
1999-06-30
Support Year
14
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Oregon Health and Science University
Department
Type
Schools of Medicine
DUNS #
009584210
City
Portland
State
OR
Country
United States
Zip Code
97239
Ligon, L A; Steward, O (2000) Movement of mitochondria in the axons and dendrites of cultured hippocampal neurons. J Comp Neurol 427:340-50
Ligon, L A; Steward, O (2000) Role of microtubules and actin filaments in the movement of mitochondria in the axons and dendrites of cultured hippocampal neurons. J Comp Neurol 427:351-61
Tiedge, H; Brosius, J (1996) Translational machinery in dendrites of hippocampal neurons in culture. J Neurosci 16:7171-81
Benson, D L; Mandell, J W; Shaw, G et al. (1996) Compartmentation of alpha-internexin and neurofilament triplet proteins in cultured hippocampal neurons. J Neurocytol 25:181-96
Steward, O (1995) Targeting of mRNAs to subsynaptic microdomains in dendrites. Curr Opin Neurobiol 5:55-61
Benson, D L; Watkins, F H; Steward, O et al. (1994) Characterization of GABAergic neurons in hippocampal cell cultures. J Neurocytol 23:279-95
Kleiman, R; Banker, G; Steward, O (1994) Development of subcellular mRNA compartmentation in hippocampal neurons in culture. J Neurosci 14:1130-40
Craig, A M; Banker, G (1994) Neuronal polarity. Annu Rev Neurosci 17:267-310
Craig, A M; Steward, O; Banker, G (1994) Use of HSV-1 amplicon vectors to study RNA and protein targeting in cultured hippocampal neurons. Gene Ther 1 Suppl 1:S72
Kleiman, R; Banker, G; Steward, O (1993) Inhibition of protein synthesis alters the subcellular distribution of mRNA in neurons but does not prevent dendritic transport of RNA. Proc Natl Acad Sci U S A 90:11192-6

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