cyclic nucleotide binding

Definition

Target type: molecularfunction

Binding to a cyclic nucleotide, a nucleotide in which the phosphate group is in diester linkage to two positions on the sugar residue. [GOC:ai]

Cyclic nucleotide binding is a fundamental molecular process that enables cells to respond to intracellular signaling molecules. It involves the non-covalent interaction of proteins with cyclic nucleotides, such as cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). These nucleotides act as second messengers, relaying information from extracellular signals to intracellular targets, triggering a cascade of events that ultimately regulate cellular processes. Cyclic nucleotide binding proteins typically possess a conserved domain that specifically recognizes and binds to cyclic nucleotides. This interaction is highly specific and often involves multiple amino acid residues within the binding domain that form hydrogen bonds and hydrophobic interactions with the cyclic nucleotide. Once bound, the cyclic nucleotide can induce conformational changes in the protein, altering its activity and triggering downstream signaling events. The molecular function of cyclic nucleotide binding encompasses various processes, including:

- **Activation or Inhibition of Enzyme Activity:** Many enzymes are regulated by cyclic nucleotide binding. For example, protein kinase A (PKA) is activated by cAMP binding, leading to phosphorylation of target proteins and modulation of cellular processes.
- **Regulation of Ion Channels:** Cyclic nucleotides can control the opening and closing of ion channels, affecting membrane potential and ion fluxes. For instance, cGMP regulates the activity of cyclic nucleotide-gated ion channels, which are crucial for sensory transduction in photoreceptor cells.
- **Modulation of Gene Expression:** Cyclic nucleotide binding can influence gene transcription by regulating the activity of transcription factors. cAMP, for example, activates the cAMP response element binding protein (CREB), which promotes the expression of specific genes.
- **Control of Cellular Processes:** Cyclic nucleotide binding plays a crucial role in regulating a wide range of cellular processes, including cell growth, differentiation, metabolism, and neuronal signaling.

In summary, cyclic nucleotide binding is a key molecular mechanism that allows cells to sense and respond to diverse stimuli. The specific effects of cyclic nucleotide binding depend on the target protein, the type of cyclic nucleotide involved, and the cellular context.'
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Proteins (2)

Compounds (4)