Special Issue on "New Advances in Cyclic AMP Signalling"-An Editorial Overview.

The cyclic nucleotides 3',5'-adenosine monophosphate (cyclic AMP) signalling system underlies the control of many biological events and disease processes in man. Cyclic AMP is synthesised by adenylate cyclase (AC) enzymes in order to activate effector proteins and it is then degraded by phosphodiesterase (PDE) enzymes. Research in recent years has identified a range of cell-type-specific cyclic AMP effector proteins, including protein kinase A (PKA), exchange factor directly activated by cyclic AMP (EPAC), cyclic AMP responsive ion channels (CICs), and the Popeye domain containing (POPDC) proteins, which participate in different signalling mechanisms.

The effect of the RACK1 signalling protein on the regulation of cell adhesion and cell contact guidance on nanometric grooves.

A wide variety of different cell types have been shown to respond to nanofabricated growth surfaces via the process of contact guidance, however little is known about the intracellular mechanisms that control these events. In the present study we have identified the multi-functional signalling adaptor protein, RACK1, as a novel negative regulator of contact guidance on custom-engineered nanometric grooves. We found that over-expression of RACK1 in human breast cancer cells leads to a pro-adherent morphology characterised by the formation of stress fibres and focal adhesions.