Calcitonin gene related peptide receptor

The Calcitonin Gene-Related Peptide receptor is a receptor protein found in the membrane of vertebrates that is activated by its ligand, the Calcitonin Gene-Related Peptide (CGRP). The receptor mediates its effects through activation of Gs proteins and subsequent activation of adenylyl cyclases. The coding gene (CALCRL) for the calcitonin receptor-like receptor is located on chromosome 2 in the gene locus q31-q32.

All peptides of the calcitonin-peptide group act via one of 2 G-protein coupled receptor (GPCR), the calcitonin receptor (CTR) or the calcitonin receptor-like receptor (CLR).

The heterodimerization of these GPCRs with one of three receptor activity modifying proteins (RAMP) is increased. Complex formation from several proteins is crucial for the ligand specificity and function of the receptor. The members of the calcitonin peptide family bind to the different receptors in different activities (see figure).

The CGRP receptor consists of a heterodimer with CLR and the receptor activity-modifying protein 1 (RAMP1) (McLatchie et al ). The ligand binding domain is located between RAMP and CLR (Hay et al 2016). The receptor-mediated increase of intracellular cAMP leads to an activation of protein kinase A, whereupon various factors such as ATP-dependent potassium channels, ERKs (extracellular-signal regulated kinases) and transcription factors such as CREB (cAMP response element-binding protein) are phosphorylated. This enables the transcription of target genes, among other things. The CGRP receptor is mainly expressed in smooth vascular muscles, but also by neurons of the trigeminal ganglion and certain glial cells (Eftekharis et al 2010).

Migraine: CGPR is believed to play a causal role in the development of migraine (Guo et al. 2017). This is underlined by experimental data and clinical study results obtained with monoclonal antibodies that block CGRP or the CGRP receptor highly selectively.

1. Eftekharis S et al (2013) Differentiation of nerve fibers storing CGRP and CGRP receptors in the peripheral trigeminovascular system. J Pain 14: 1289-1303
2. Guo S et al (2017) Calcitonin gene-related peptide induced migraine attacks in patients with and without familial aggregation of migraine. Cephalagia 37: 114-124
3. Hay DL et al (2016) Receptor activity-modifying proteins (RAMPs): New insight and roles. Annu Rev Pharmacol Toxicol 56: 469-487

4. Kukowski B (2018) CGRP signal transduction. Aspects of the development of migraine and current drug therapy approaches. https://www.cme point.de/Fortbildungen/2370_CGRP_CME_FINAL.pdf (taken on 1.9.2020)

5. McLatchie LM et al (1989) RAMPs regulate the transport and ligand specifity of the Calcitonin-receptor-like receptor. Nature 393: 333-339
6. Russel FA et al (2014) Calcitonin gene-related peptides: physiology and pathophysiology. Physiol Rev 94: 1099-1142