Science Topics – 174
Our previous research has revealed that a molecule called "voltage-sensing phosphatase (VSP)" functions in sperm (Kawai et al., PNAS, 2019). VSP senses membrane potential and exhibits enzymatic activity, altering the levels of a membrane lipid known as phosphatidylinositol bisphosphate (PIP2). This mechanism is crucial for the regulation of sperm motility; however, how VSP senses membrane potential in sperm remains unclear. In this study, we investigated sperm at different stages of maturation using mice and found that VSP's effects are particularly pronounced in immature sperm. Furthermore, we generated genetically manipulated mice with altered voltage sensitivity of VSP and examined their sperm. As a result, we observed abnormal enzymatic activity in immature sperm and impaired motility in mature sperm. These findings suggest that the "electrical signals" in immature sperm are crucial for maintaining proper membrane composition, highlighting a new significance of electrical signals in sperm.
Kawai T, Morioka S, Miyata H, Andriani RT, Akter S, Toma G, Nakagawa T, Oyama Y, Iida-Norita R, Sasaki J, Watanabe M, Sakimura K, Ikawa M, Sasaki Y, Okamura Y The Significance of Electrical Signals in Maturing Spermatozoa for Phosphoinositide Regulation Through Voltage-Sensing Phosphatase Nature Communications 15:7289 (2024)
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We found that maturing sperm sense the membrane potential to regulate membrane lipid composition
Laboratory of Integrative Physiology, Graduate School of Medicine, Osaka University