Signaling themes shared between peptide and steroid hormones at the plasma membrane.

Steroid hormone receptors are primarily thought of as transcriptional regulators that are activated by ligand binding. However, there is also evidence for "nongenomic" actions of steroid hormones. Cheryl Watson summarizes a recent meeting that brought together researchers exploring these rapid effects of steroid hormones that occur in the absence of new protein synthesis. Current evidence for the existence of membrane steroid receptors, which may or may not be related to the well-known nuclear receptors, is discussed.