How Worms Sense Oxygen

Science's STKE  20 Jul 2004:
Vol. 2004, Issue 242, pp. tw262-TW262
DOI: 10.1126/stke.2422004TW262

New evidence indicates that soluble guanylate cyclases may serve as oxygen sensors. Members of the guanylate cyclase family are well known as targets for regulation by nitric oxide, and Gray et al. show that a similar heme-mediated interaction appears to allow regulation of the guanylate cyclase homologue GCY-35 in Caenorhabditis elegans by oxygen. In exploring responses of the worm to oxygen, the authors found that the animals avoid both hypoxia and hyperoxia. The response to hyperoxia was lost in mutants with nonfunctional GCY-35, which is expressed in sensory neurons. Oxygen binding to GCY-35 was detected by ultraviolet/visible spectroscopic analysis, though it is not yet known whether cyclase activity is altered by such interaction. GCY-35 appeared to influence neuronal function by acting upstream of the cyclic nucleotide-gated channels TAX-2 and TAX-4 because tax mutants also failed to avoid hyperoxia.

J. M. Gray, D. S. Karow, H. Lu, A. J. Chang, J. S. Chang, R. E. Ellis, M. A. Marietta, C. I. Bargmann, Oxygen sensation and social feeding mediated by a C. elegans guanylate cyclase homologue. Nature 430, 317-322 (2004). [Online Journal]