C11orf20 Inhibitors

The Catsper channel auxiliary subunit zeta, known as CATSPERζ, is a vital component of the CATSPER complex, which is a sperm-specific, calcium-permeable, pH-sensitive channel essential for male fertility. The channel mediates the influx of calcium ions into sperm, which is necessary for hyperactivated motility and the acrosome reaction, both of which are crucial for successful fertilization.The CATSPER complex consists of several subunits, with CATSPER1-4 forming the pore of the channel and auxiliary subunits, including CATSPERζ, contributing to the regulation and proper functioning of the channel. CATSPERζ's role, while not forming the ion-conducting pore itself, is imperative in the assembly, localization, and modulation of the CATSPER channel. It is thought to influence the channel's biophysical properties and may participate in the signaling pathways that activate the CATSPER channel in response to environmental cues within the female reproductive tract.

Located in the principal piece of the sperm tail, the CATSPERζ, along with the rest of the CATSPER complex, is activated in the alkaline conditions of the female genital tract and by other stimuli associated with the proximity of the egg. Upon activation, CATSPER channels allow an influx of calcium ions, which triggers a series of events leading to the hyperactivated motility required for sperm to navigate the female reproductive system and reach the egg. This hyperactivation is characterized by a highly vigorous and asymmetrical flagellar beating pattern, which is distinct from the more symmetrical and less forceful movement observed in non-capacitated sperm.The importance of CATSPERζ and the entire CATSPER complex is underscored by the fact that mutations or deficiencies in these proteins can lead to male infertility due to impaired sperm function, demonstrating the essential role of calcium signaling in sperm motility and fertilization.