An MBoC Favorite: Ca2+ entry through store-operated channels in mouse sperm is initiated by egg ZP3 and drives the acrosome reaction
نویسنده
چکیده
To fertilize eggs, mammalian sperm must first undergo a form of cellular exocytosis called the acrosome reaction. In 1983, my laboratory reported that nanomolar concentrations of ZP3, one of three zona pellucida glycoproteins from mouse eggs, induced mouse sperm to undergo the acrosome reaction in vitro. Seven years later, this article from Florman’s laboratory (O’Toole et al., 2000) revealed that when ZP3 binds to sperm heads, it generates a sustained influx of Ca2+ through store depletion–activated channels that function to refill internal Ca2+ stores and triggers the acrosome reaction. In the presence of egg ZP3, Ca2+ levels in sperm increased nearly 2.5-fold, from ∼159 to ∼396 nm. This article provided a comprehensive model for the ionic events responsible for ZP3-induced signal transduction in sperm during mammalian fertilization.
منابع مشابه
Ca(2+) entry through store-operated channels in mouse sperm is initiated by egg ZP3 and drives the acrosome reaction.
Fertilization occurs after the completion of the sperm acrosome reaction, a secretory event that is triggered during gamete adhesion. ZP3, an egg zona pellucida glycoprotein, produces a sustained increase of the internal Ca(2+) concentration in mouse sperm, leading to acrosome reactions. Here we show that the sustained Ca(2+) concentration increase is due to the persistent activation of a Ca(2+...
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Sperm adhesion to egg zonae pellucidae initiates sperm acrosome reactions, an exocytotic event that is an early step during fertilization. Previously, it was suggested that zona pellucida-evoked Ca2+ entry into sperm through low voltage-activated Ca2+ channels is an essential step in acrosome reactions, based on the inhibitory effects of Ca2+ channel antagonists. However, analysis of this chann...
متن کاملRegulating the acrosome reaction.
The acrosome reaction is a secretory event that must be completed by the sperm of many animal species prior to fusion with eggs. In mammals, exocytosis in triggered by ZP3, a glycoprotein component of the egg pellucida, following gamete contact. ZP3 promotes a sustained influx of Ca2+ into sperm that is necessary for the acrosome reaction. Here, we discuss the mechanism by which ZP3 generates C...
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The sperm acrosome reaction is a Ca(2+)-dependent secretory event required for fertilization. Adhesion to the egg's zona pellucida promotes Ca2+ influx through voltage-sensitive channels, thereby initiating secretion. We used potentiometric fluorescent probes to determine the role of sperm membrane potential in regulating Ca2+ entry. ZP3, the glycoprotein agonist of the zona pellucida, depolari...
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The influx of Ca2+ and its subsequent intracellular increase are required for the acrosome reaction of sea urchin sperm to occur. Spermatozoa must undergo this reaction, which is triggered by the egg jelly, in order to fertilize the egg. Here, the egg jelly-induced Ca2+ influx mechanisms have been studied in sperm loaded with FURA-2 using Mn2+ under the assumption that this divalent ion is an i...
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