neuropeptide signaling pathway

Definition

Target type: biologicalprocess

A G protein-coupled receptor signaling pathway initiated by a neuropeptide binding to its receptor on the surface of a target cell, and ending with the regulation of a downstream cellular process. [GOC:mah, ISBN:0815316194]

Neuropeptide signaling pathways are complex and multifaceted processes that involve the synthesis, release, transport, and reception of neuropeptides, which are small protein-like molecules that act as chemical messengers in the nervous system. These pathways play crucial roles in regulating a wide range of physiological functions, including mood, appetite, sleep, stress response, pain perception, and cardiovascular function.

The process begins with the synthesis of neuropeptides within neuronal cells. Neuropeptide precursors are synthesized as larger proteins that undergo post-translational modifications, including cleavage and processing, to generate the mature neuropeptides. Once synthesized, neuropeptides are packaged into secretory vesicles and transported to the axon terminal, where they are stored until released.

Neuropeptide release is triggered by neuronal activity, typically in response to an action potential. Upon arrival of the action potential, calcium ions enter the axon terminal and trigger the fusion of the secretory vesicles with the presynaptic membrane. This fusion event results in the release of neuropeptides into the synaptic cleft, the space between the presynaptic and postsynaptic neurons.

Once released, neuropeptides diffuse across the synaptic cleft and bind to specific receptors on the postsynaptic neuron. These receptors are typically G protein-coupled receptors (GPCRs), which are transmembrane proteins that activate intracellular signaling cascades upon ligand binding. Neuropeptide binding to GPCRs can lead to a variety of cellular responses, including changes in gene expression, ion channel activity, and enzyme activity.

The effects of neuropeptide signaling can be localized or widespread. In some cases, neuropeptides act on neighboring neurons within the same brain region, while in other cases, they can travel long distances through the bloodstream to reach distant target tissues. The duration of neuropeptide signaling can also vary, with some neuropeptides having rapid and transient effects, while others have more prolonged and sustained effects.

The complexity of neuropeptide signaling pathways arises from the large number of neuropeptides and receptors involved. The human genome encodes hundreds of different neuropeptides, each with its own unique structure and function. Similarly, there are numerous GPCRs that are specifically activated by different neuropeptides. This diversity of neuropeptides and receptors allows for a wide range of signaling possibilities, which contribute to the intricate regulation of neuronal function and behavior.

In addition to their role in normal physiological function, neuropeptide signaling pathways can also be dysregulated in various disease states. For example, disruptions in neuropeptide signaling have been implicated in neurodevelopmental disorders, neurodegenerative diseases, psychiatric disorders, and metabolic disorders. Therefore, understanding the intricacies of neuropeptide signaling is crucial for developing novel therapeutic strategies to target these diseases.'
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Proteins (49)

Compounds (622)