New insights into sperm physiology regulation: Enlightenment from G‐protein‐coupled receptors

Abstract

AbstractBackgroundG‐protein‐coupled receptors are critical in many physiological and pathological processes in various organs. Serving as the control panel for sensing extracellular stimuli, G‐protein‐coupled receptors recognise various ligands, including light, temperature, odours, pheromones, hormones, neurotransmitters, chemokines, etc. Most recently, G‐protein‐coupled receptors residing in spermatozoa have been found to be indispensable for sperm function.ObjectiveHere, we have summarised cutting‐edge findings on the functional mechanisms of G‐protein‐coupled receptors that are known to be associated with sperm functions and the activation of their downstream effectors, providing new insights into the roles of G‐protein‐coupled receptors in sperm physiology.ResultsEmerging studies hint that alterations in G‐protein‐coupled receptors could affect sperm function, implicating their role in fertility, but solid evidence needs to be continuing excavated with various means. Several members of the G‐protein‐coupled receptor superfamily, including olfactory receptors, opsins, orphan G‐protein‐coupled receptors, CXC chemokine receptor 4, CC chemokine receptor 5 and CC chemokine receptor 6 as well as their downstream effector β‐arrestins, etc., were suggested to be essential for sperm motility, capacitation, thermotaxis, chemotaxis, Ca2+ influx through CatSper channel and fertilisation capacity.ConclusionThe present review provides a comprehensive overview of studies describing G‐protein‐coupled receptors and their potential action in sperm function. We also present a critical discussion of these issues, and a possible framework for future investigations on the diverse ligands, biological functions and cell signalling of G‐protein‐coupled receptors in spermatozoa. Here, the G‐protein‐coupled receptors and their related G proteins that specifically were identified in spermatozoa were summarised, and provided references valuable for further illumination, despite the evidence that is not overwhelming in most cases.