In this volume of Reviews of Physiology there are three outstanding contributions, the first on Selenium-containing proteins in mammals and other forms of life, and the second on constitutively active and G-protein coupled inward rectifier K+ channels: Kir2.0 and Kir3.0 and the third on Chloroplast quest: a journey from the cytosol into the chloroplast and beyond.

Contributions by: A. Kyriakopoulos, D. Behne, P.R. Stanfield, S. Nakajima, Y. Nakajima, U.C. Vothknecht, J. Soll