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Ca2؉ induction of a subset of cellular and viral immediate-early activation genes in lymphocytes has been previously mapped to response elements recognized by the MEF2 family of transcription factors. Here, we demonstrate that Ca 2؉ activation of MEF2 response elements in T lymphocytes is mediated in synergy by two Ca 2؉ /calmodulin-dependent enzymes, the phosphatase calcineurin, and the kinase type IV/Gr (CaMKIV/Gr), which promote transcription by the MEF2 family members MEF2A and MEF2D. Calcineurin up-regulates the activity of both factors by an NFAT-dependent mechanism, while CaMKIV/Gr selectively and independently activates MEF2D. These results identify MEF2 proteins as effectors of a pathway of gene induction in T lymphocytes which integrates diverse Ca 2؉ activation signals and may be broadly operative in several tissues.

The ability to remember potential dangers in an environment is necessary to the survival of animals and humans. The cyclic AMP responsive element binding protein (CREB) is a key transcription factor in synaptic plasticity and memory consolidation. We have found that in CaMKIV(-/-) mice--which are deficient in a component of the calcium calmodulin-dependent protein kinase (CaMK) pathway, a major pathway of CREB activation--fear memory, but not persistent pain, was significantly reduced. CREB activation by fear conditioning and synaptic potentiation in the amygdala and cortical areas was reduced or blocked. We propose that cognitive memory related to a noxious shock can be disassociated from behavioral responses to tissue injury and inflammation.

The ability to remember potential dangers in an environment is necessary to the survival of animals and humans. The cyclic AMP responsive element binding protein (CREB) is a key transcription factor in synaptic plasticity and memory consolidation. We have found that in CaMKIV(-/-) mice--which are deficient in a component of the calcium calmodulin-dependent protein kinase (CaMK) pathway, a major pathway of CREB activation--fear memory, but not persistent pain, was significantly reduced. CREB activation by fear conditioning and synaptic potentiation in the amygdala and cortical areas was reduced or blocked. We propose that cognitive memory related to a noxious shock can be disassociated from behavioral responses to tissue injury and inflammation.