Relaxin GPCR Assays

Background of Relaxin Receptors

The relaxin family peptide (RXFP) receptors are a family of G protein-coupled receptors, that mediate the hormonal and neuropeptide actions on their endogenous ligands relaxin family peptides and insulin-like peptides (INSL). Relaxin is characterized by vasodilatory, anti-fibrotic, angiogenic, anti-apoptotic, and anti-inflammatory properties, which has therapeutic effects on organ damage prevention, cardiovascular diseases, renal disease, and asthma. Chronic RXFP1 targeting therapies are under development.

Fig.1 Structural features of the relaxin family peptide receptor RXFP1. (Bathgate, 2013)

Distributions and Functions of Relaxin Receptors

The RXFP receptors are involved in the regulation of the cardiovascular system, formation of connective tissue and bone, reproduction, stress responses, anxiety and mood, arousal, spatial and social memory, and motivation. They are broadly distributed in the brain, reproductive tissues in both males and females, including semen, testis, ovary, pubic symphysis, cervix, uterus, and mammary glands, as well as in the heart, kidney, lung, thyroid, and colon.

Subtypes and Mechanisms of Relaxin Receptors

The family of RXFP receptors has 4 subtypes of G protein-coupled receptors, including RXFP1, RXFP2, RXFP3, and RXFP4 receptors. They promote signal transduction through G_s and G_i/G_o proteins.

Reference

1. Bathgate, R. A. D.; et al. Relaxin family peptides and their receptors. Physiological reviews. 2013, 93(1): 405-480.