MITOCHONDRIAL EFFECTS ON SENSITIVITY TO ANESTHETICS

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The long term goal of this laboratory is to understand at the molecular level how the volatile anesthetics work. Such knowledge is certainly vital for future rational design of these compounds; it may also prove useful as a probe in understanding the basis of consciousness itself. We have used the nematode C. elegans to identify genes that control the behavior of this animal in volatile anesthetics. A mutation in one of these genes, gas-1,is hypersensitive to all volatile anesthetics tested, and overrides the effects of any other mutation on the animal's behavior in anesthetic gases. gas-1 codes for one subunit of the first protein complex (complex l) of the mitochondrial electron transport chain. We propose to analyze at the molecular level how this protein, the 49kDA subunit of NADH ubiquinone oxidoreductase, affects anesthetic sensitivity in C. elegans. The specific aims of this proposal are to: 1. identity the expression of this gene both temporally and spatially. Powerful techniques unique to C. elegans make it possible to know the individual cells in which this gene operates well as to pinpoint developmental stages crucial to the gene's function. 2. measure the effects of gas-1 on oxidative phosphorylation and membrane peroxidation. Both of these processes are dependent on complex l; either or both may be responsible for the gene's control of behavior in volatile anesthetics. 3.find additional mutations in gas-1 and other mitochondrial proteins. We must find more alleles of gas-1 to correlate structure of its protein product to its function. In addition, by screening for suppressors or enhancers of gas-1, we may find other genes that code for mitochondrial proteins that affect anesthetic response. Newly Identified genes will also be studied for their effect on oxidative phosphorylation and membrane peroxidation. We may ultimately identify a functional cluster of proteins that is responsible for the effect of volatile anesthetics in C. elegans. gas-1 profoundly affects anesthetic sensitivity in C. elegans; it is the gene that appears closest to a true anesthetic target in this model. This is consistent with earlier studies which identified complex l as the most sensitive protein complex of the electron transport chain to volatile anesthetics. A precise understanding of gas-1 's molecular interactions with volatile anesthetics will provide invaluable information as to how volatile anesthetics work at the molecular level.