Cyclic nucleotides are important second messenger molecules in signal transduction. Cyclic AMP (cAMP) particularly activates protein kinases that are involved in numerous signal transduction and metabolic pathways. Cyclic GMP (cGMP) mainly activates the cGMP-dependent protein kinase G and is involved in physiological processes such as eye vision, relaxation of smooth musculature and regulation of the Insuline level.
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