Nucleocytoplasmic shuttling of signal transducers

The nuclear translocation of signal-transduction proteins is an essential step in the control of gene expression by numerous extracellular signals. Recent studies have shown that some signal transducers are imported into the nucleus by nuclear-localization-signal- and importin-independent processes. Such a mechanism could allow bidirectional movement across the nuclear envelope. Extracellular signals modify the affinity between signal transducers and anchoring factors, thereby regulating the nucleocytoplasmic shuttling of signalling molecules.