M.J.R. and Z.S. contributed equally to this work.
Cyclic AMP response element-binding (CREB)-like proteins in a molluscan brain: cellular localization and learning-induced phosphorylation
Version of Record online: 2 SEP 2003
European Journal of Neuroscience
Volume 18, Issue 5, pages 1223–1234, September 2003
How to Cite
Ribeiro, M. J., Serfőző, Z., Papp, A., Kemenes, I., O'Shea, M., Yin, J. C. P., Benjamin, P. R. and Kemenes, G. (2003), Cyclic AMP response element-binding (CREB)-like proteins in a molluscan brain: cellular localization and learning-induced phosphorylation. European Journal of Neuroscience, 18: 1223–1234. doi: 10.1046/j.1460-9568.2003.02856.x
- Issue online: 2 SEP 2003
- Version of Record online: 2 SEP 2003
- Received 11 June 2003, accepted 30 June 2003
- classical conditioning;
- feeding network;
- Lymnaea brain;
- transcription factors
The phosphorylation and the binding to DNA of the nuclear transcription factor, cyclic adenosine 3′,5′-monophosphate (cAMP) response element-binding protein (CREB) are conserved key steps in the molecular cascade leading to the formation of long-term memory (LTM). Here, we characterize, for the first time, a CREB1-like protein in the central nervous system (CNS) of Lymnaea, a model system used widely for the study of the fundamental mechanisms of learning and memory. We demonstrate cAMP response element (CRE)-binding activity in CNS protein extracts and show that one of the CRE-binding proteins is recognized by a polyclonal antibody raised to mammalian (human) CREB1. The same antibody detects specific CREB1 immunoreactivity in CNS extracts and in the nuclei of most neurons in the brain. Moreover, phospho–CREB1-specific immunoreactivity is increased significantly in protein extracts of the CNS by forskolin, an activator of adenylate cyclase. The forskolin-induced increase in phospho–CREB1 immunoreactivity is localized to the nuclei of CNS neurons, some of which have an important role in the formation of LTM. Significantly, classical food–reward conditioning increases phospho–CREB1 immunoreactivity in Lymnaea CNS protein extracts. This increase in immunoreactivity is specific to the ganglia that contain the feeding circuitry, which undergoes cellular changes after classical conditioning. This work establishes the expression of a highly conserved functional CREB1-like protein in the CNS of Lymnaea and opens the way for a detailed analysis of the role of CREB proteins in LTM formation in this model system.