Inhibition of adipogenesis: a new job for the ER Ca2+ pool

Adipogenesis is the process of differentiation of adipocytes from mesenchymal multipotent cells through adipocyte precursors. In this issue, a study by the groups of Opas and Michalak (Szabo, E., Y. Qiu, S. Baksh, M. Michalak, and M. Opas. 2008. J. Cell. Biol. 182:103-116) demonstrates that this process is repressed by increasing intracellular Ca(2+), which, in turn, is dependent on the expression of calreticulin, the major Ca(2+)-binding protein of the endoplasmic reticulum lumen.