Plant biology

Receptors Have a Gas in ER

Science's STKE  04 Jun 2002:
Vol. 2002, Issue 135, pp. tw199-TW199
DOI: 10.1126/stke.2002.135.tw199

In plants, the gaseous hormone ethylene has a wide range of effects. It acts through members of a family of receptors, the most well characterized of which is ETR1. ETR1 has histidine kinase activity, but precisely how it signals is not known. Ethylene is soluble in aqueous or lipid environments and can diffuse anywhere in the cell. Nevertheless, its receptors are transmembrane proteins that actually bind ethylene in the transmembrane domain. Chen et al. used aqueous two-phase partitioning, sucrose density gradient fractionation, and immunoelectron microscopy to explore distribution of ETR1 and conclude that it is predominantly localized in membranes of the endoplasmic reticulum (ER). The authors note that ABP1, a soluble binding protein for another plant hormone, auxin, is also localized in the ER, suggesting that the ER may be a particularly important location for plant cell signaling.

Y.-F. Chen, M. D. Randlett, J. L. Findell, G. E. Schaller, Localization of the ethylene receptor ETR1 to the endoplasmic reticulum of Arabidopsis. J. Biol. Chem. 277, 19861-19866 (2002). [Abstract] [Full Text]