Potassium currents are important for controlling the membrane potential and, therefore, the level of electrical activity in neurons, muscles and various other cell types. Although the physiological properties of K+ channels have been studied for a number of years, lack of either a rich tissue source or a good ligand has prevented the biochemical purification of any K+ channel. Using the genetic approach available in Drosophila, the first complete sequence for a K+ channel was recently reported from the Shaker locus of Drosophila. A homologous gene expressed in the mouse brain was subsequently cloned. Here we propose to extend our studies on the probable mouse-brain K+ channel gene, called MBK1. We will address the following specific aims: 1) To express physiologically the MBK1 cDNA, thereby confirming that it encodes a K+ channel component. 2) To study the function of residues that are conserved between Shaker and MBK1 using in vitro mutagenesis. 3) To characterize the MBK1 protein, including the channel of which it is likely to be a part. 4) To identify the tissues that express MBK1 and, within the brain, to localize MBK1 expression by in situ hybridization and the MBK1 protein using immunocytochemistry. 5) To characterize the MBK1 gene, its structure and regulatory elements. 6) To identify the chromosomal location of MBK1 and to determine if the MBK1 locus correlates to any behavioral mutants in mice. Answers from these studies may help to explain, at the molecular level, how membrane excitability is controlled and, in diseases like epilepsy, periodic paralysis or diabetes, how uncontrolled membrane excitability may come about.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS027206-02
Application #
3413412
Study Section
Neurology C Study Section (NEUC)
Project Start
1989-04-01
Project End
1992-03-31
Budget Start
1990-04-01
Budget End
1991-03-31
Support Year
2
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Medicine
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Grigg, J J; Brew, H M; Tempel, B L (2000) Differential expression of voltage-gated potassium channel genes in auditory nuclei of the mouse brainstem. Hear Res 140:77-90
Hallows, J L; Tempel, B L (1998) Expression of Kv1.1, a Shaker-like potassium channel, is temporally regulated in embryonic neurons and glia. J Neurosci 18:5682-91
Allen, M L; Koh, D S; Tempel, B L (1998) Cyclic AMP regulates potassium channel expression in C6 glioma by destabilizing Kv1.1 mRNA. Proc Natl Acad Sci U S A 95:7693-8
Street, V A; Tempel, B L (1997) Physical mapping of potassium channel gene clusters on mouse chromosomes three and six. Genomics 44:110-7
Smart, S L; Bosma, M M; Tempel, B L (1997) Identification of the delayed rectifier potassium channel, Kv1.6, in cultured astrocytes. Glia 20:127-34
Street, V A; Hopkins, W F; Tempel, B L (1996) Genomic structure, sequence, and physiological expression of mKv 1.5, a mouse potassium channel gene. Epilepsy Res Suppl 12:165-75
Street, V A; Robinson, L C; Erford, S K et al. (1995) Molecular genetic analysis of distal mouse chromosome 6 defines gene order and positions of the deafwaddler and opisthotonos mutations. Genomics 29:123-30
Lock, L F; Gilbert, D J; Street, V A et al. (1994) Voltage-gated potassium channel genes are clustered in paralogous regions of the mouse genome. Genomics 20:354-62
Wang, H; Kunkel, D D; Schwartzkroin, P A et al. (1994) Localization of Kv1.1 and Kv1.2, two K channel proteins, to synaptic terminals, somata, and dendrites in the mouse brain. J Neurosci 14:4588-99
Hopkins, W F; Demas, V; Tempel, B L (1994) Both N- and C-terminal regions contribute to the assembly and functional expression of homo- and heteromultimeric voltage-gated K+ channels. J Neurosci 14:1385-93

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