Extracellular-signal-regulated kinase signalling in neurons

Extracellular-signal-regulated kinases (ERKs) are emerging as important reg ulators of neuronal function. Recent advances have increased our understand ing of ERK signalling at the molecular level. In particular, it has became evident that multiple second messengers, such as cyclic adenosine monophosp hate, protein kinase A, calcium, and diacylglycerol, can control ERK signal ling via the small G proteins Ras and Rap1. These findings may explain the role of ERKs in the regulation of activity-dependent neuronal events, such as synaptic plasticity, long-term potentiation and cell survival. Moreover, they allow us to begin to develop a model to understand both the control o f ERKs at the subcellular level and the generation of ERK signal specificit y.