scholarly journals Molecular physiology and pathology of Ca2+-conducting channels in the plasma membrane of mammalian sperm

Reproduction ◽  
2005 ◽  
Vol 129 (3) ◽  
pp. 251-262 ◽  
Author(s):  
Ricardo Felix
Keyword(s):  
Plasma Membrane ◽  
Acrosome Reaction ◽  
Current Evidence ◽  
Molecular Physiology ◽  
Mammalian Sperm ◽  
Fertilizing Ability ◽  
Intracellular Ca ◽  
Gene Defects ◽  
Sperm Fertilizing Ability ◽  
Sperm Functions

Current evidence indicates that mechanisms controlling the intracellular Ca2+concentration play pivotal roles in determining sperm fertilizing ability. Multiple Ca2+-permeable channels have been identified and characterized in the plasma membrane and in the acrosome membrane of mammalian sperm. This review summarizes the recent findings and assesses the evidence suggesting that these channels play roles in controlling a host of sperm functions ranging from motility to the acrosome reaction, and describes recent advances in the identification of the underlying gene defects of inherited sperm Ca2+channelopathies.

Defining the roles of Ca2+ — permeable channels in sperm

2006 ◽  
Vol 1 (4) ◽  
pp. 506-529 ◽  
Author(s):  
M. Sadiqul Islam
Keyword(s):  
Plasma Membrane ◽  
Ion Channels ◽  
Acrosome Reaction ◽  
Vital Role ◽  
Male And Female ◽  
Fertilizing Ability ◽  
Sperm Fertilizing Ability

AbstractIon channels exert a vital role in the dialogue between male and female gametes and thus in the generation of new individuals in many species. Intracellular Ca2+ is possibly the key messenger between gametes. Different Ca2+-permeable channels have been detected in the plasma membrane and in the organelle-like acrosome membrane of sperm, which play vital roles in determining sperm fertilizing ability. Recent reports from several laboratories have adequately documented that the Ca2+-permeable channels of a sperm control a variety of functions ranging from motility to the acrosome reaction. In this article, we have reviewed the data from our and other laboratories, and have documented the mechanisms of different Ca2+-permeable channels involved in the fertilization event.

scholarly journals Asterosap, an Egg Jelly Peptide, Elevate Intracellular Ca2+ and Activate the Motility of Spermatozoa

2013 ◽  
Vol 19 (1) ◽  
pp. 79-88 ◽  
Author(s):  
MS Islam ◽  
T Akhter ◽  
M Matsumoto
Keyword(s):  
Plasma Membrane ◽  
Cyclic Gmp ◽  
Guanylyl Cyclase ◽  
Acrosome Reaction ◽  
Nickel Chloride ◽  
Selective Inhibitor ◽  
Ion Flux ◽  
Intracellular Ca ◽  
A Cell ◽  
Egg Jelly

Components from the outer envelopes of the egg that influence the flagellar beating and acrosome reaction of spermatozoa are regulated by ion flux across the plasma membrane. Asterosap, a sperm-activating peptide from the starfish egg jelly layer, causes a transient increase in intracellular cyclic GMP (cGMP) through the activation of the asterosap receptor, a guanylyl cyclase (GC), and causes an increase in intracellular Ca2+. Here we describe the pathway of asterosap-induced Ca2+ elevation using different Ca2+ channel antagonists. Fluo-4 AM, a cell permeable Ca2+ sensitive dye was used to determine the channel caused by the asterosap-induced Ca2+ elevation in spermatozoa. Different L-type Ca2+ channel antagonists, a non specific Ca2+ channel antagonist (nickel chloride), and a store-operated Ca2+ channel (SOC) antagonist do not show any significant response on asterosap-induced Ca2+ elevation, whereas KB-R7943, a selective inhibitor against Na+/Ca2+ exchanger (NCX) inhibited effectively. We also analyzed the flagellar movement of spermatozoa in artificial seawater (ASW) containing the asterosap at 100 nM ml?1. We found that spermatozoa swam vigorously with more symmetrical flagellar movement in asterosap than in ASW and KB-R7943 significantly inhibited the flagellar movement.DOI: http://dx.doi.org/10.3329/pa.v19i1.17358 Progress. Agric. 19(1): 79 - 88, 2008 

scholarly journals Calpain modulates capacitation and acrosome reaction through cleavage of the spectrin cytoskeleton

Reproduction ◽  
2010 ◽  
Vol 140 (5) ◽  
pp. 673-684 ◽  
Author(s):  
Yadira Bastián ◽  
Ana L Roa-Espitia ◽  
Adela Mújica ◽  
Enrique O Hernández-González
Keyword(s):  
Plasma Membrane ◽  
Guinea Pig ◽  
Acrosome Reaction ◽  
Mammalian Species ◽  
Physiological Changes ◽  
Signal Transducer ◽  
Mammalian Sperm ◽  
Important Player ◽  
Calpain 2 ◽  
Spectrin Cytoskeleton

Research on fertilization in mammalian species has revealed that Ca2+is an important player in biochemical and physiological events enabling the sperm to penetrate the oocyte. Ca2+is a signal transducer that particularly mediates capacitation and acrosome reaction (AR). Before becoming fertilization competent, sperm must experience several molecular, biochemical, and physiological changes where Ca2+plays a pivotal role. Calpain-1 and calpain-2 are Ca2+-dependent proteases widely studied in mammalian sperm; they have been involved in capacitation and AR but little is known about their mechanism. In this work, we establish the association of calpastatin with calpain-1 and the changes undergone by this complex during capacitation in guinea pig sperm. We found that calpain-1 is relocated and translocated from cytoplasm to plasma membrane (PM) during capacitation, where it could cleave spectrin, one of the proteins of the PM-associated cytoskeleton, and facilitates AR. The aforementioned results were dependent on the calpastatin phosphorylation and the presence of extracellular Ca2+. Our findings underline the contribution of the sperm cytoskeleton in the regulation of both capacitation and AR. In addition, our findings also reveal one of the mechanisms by which calpain and calcium exert its function in sperm.

Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels

2003 ◽  
Vol 83 (1) ◽  
pp. 117-161 ◽  
Author(s):  
Edward Perez-Reyes
Keyword(s):  
Plasma Membrane ◽  
Action Potentials ◽  
Low Voltage ◽  
Absence Epilepsy ◽  
Molecular Physiology ◽  
Comprehensive Description ◽  
Cellular Processes ◽  
Repeat Structure ◽  
Intracellular Ca ◽  
Low Threshold

T-type Ca2+ channels were originally called low-voltage-activated (LVA) channels because they can be activated by small depolarizations of the plasma membrane. In many neurons Ca2+ influx through LVA channels triggers low-threshold spikes, which in turn triggers a burst of action potentials mediated by Na+ channels. Burst firing is thought to play an important role in the synchronized activity of the thalamus observed in absence epilepsy, but may also underlie a wider range of thalamocortical dysrhythmias. In addition to a pacemaker role, Ca2+ entry via T-type channels can directly regulate intracellular Ca2+ concentrations, which is an important second messenger for a variety of cellular processes. Molecular cloning revealed the existence of three T-type channel genes. The deduced amino acid sequence shows a similar four-repeat structure to that found in high-voltage-activated (HVA) Ca2+ channels, and Na+ channels, indicating that they are evolutionarily related. Hence, the α1-subunits of T-type channels are now designated Cav3. Although mRNAs for all three Cav3 subtypes are expressed in brain, they vary in terms of their peripheral expression, with Cav3.2 showing the widest expression. The electrophysiological activities of recombinant Cav3 channels are very similar to native T-type currents and can be differentiated from HVA channels by their activation at lower voltages, faster inactivation, slower deactivation, and smaller conductance of Ba2+. The Cav3 subtypes can be differentiated by their kinetics and sensitivity to block by Ni2+. The goal of this review is to provide a comprehensive description of T-type currents, their distribution, regulation, pharmacology, and cloning.

scholarly journals RANTES and human sperm fertilizing ability: effect on acrosome reaction and sperm/oocyte fusion

2008 ◽  
Vol 14 (7) ◽  
pp. 387-391 ◽  
Author(s):  
A. Barbonetti ◽  
M.R.C. Vassallo ◽  
C. Antonangelo ◽  
V. Nuccetelli ◽  
A. D'Angeli ◽  
...  
Keyword(s):  
Acrosome Reaction ◽  
Human Sperm ◽  
Fertilizing Ability ◽  
Sperm Fertilizing Ability

scholarly journals Role of actin cytoskeleton in mammalian sperm capacitation and the acrosome reaction

Reproduction ◽  
2005 ◽  
Vol 129 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Haim Breitbart ◽  
Gili Cohen ◽  
Sara Rubinstein
Keyword(s):  
Plasma Membrane ◽  
Zona Pellucida ◽  
Acrosome Reaction ◽  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Mammalian Sperm ◽  
Acrosomal Membrane ◽  
Close Proximity ◽  
Sperm Plasma Membrane ◽  
To Come

In order to fertilize, the mammalian spermatozoa should reside in the female reproductive tract for several hours, during which they undergo a series of biochemical modifications collectively called capacitation. Only capacitated sperm can undergo the acrosome reaction after binding to the egg zona pellucida, a process which enables sperm to penetrate into the egg and fertilize it. Polymerization of globular (G)-actin to filamentous (F)-actin occurs during capacitation, depending on protein kinase A activation, protein tyrosine phosphorylation, and phospholipase D activation. F-actin formation is important for the translocation of phospholipase C from the cytosol to the sperm plasma membrane during capacitation. Prior to the occurrence of the acrosome reaction, the F-actin should undergo depolymerization, a necessary process which enables the outer acrosomal membrane and the overlying plasma membrane to come into close proximity and fuse. The binding of the capacitated sperm to the zona pellucida induces a fast increase in sperm intracellular calcium, activation of actin severing proteins which break down the actin fibers, and allows the acrosome reaction to take place.

scholarly journals Ca2+-stores in sperm: their identities and functions

Reproduction ◽  
2009 ◽  
Vol 138 (3) ◽  
pp. 425-437 ◽  
Author(s):  
Sarah Costello ◽  
Francesco Michelangeli ◽  
Katherine Nash ◽  
Linda Lefievre ◽  
Jennifer Morris ◽  
...  
Keyword(s):  
Acrosome Reaction ◽  
Somatic Cells ◽  
Functional Interaction ◽  
Mammalian Sperm ◽  
Intracellular Ca ◽  
Principal Piece ◽  
Oscillations And Waves ◽  
Molecular Components ◽  
Cellular Ca ◽  
Discrete Functions

Intracellular Ca2+stores play a central role in the regulation of cellular [Ca2+]iand the generation of complex [Ca2+] signals such as oscillations and waves. Ca2+signalling is of particular significance in sperm cells, where it is a central regulator in many key activities (including capacitation, hyperactivation, chemotaxis and acrosome reaction) yet mature sperm lack endoplasmic reticulum and several other organelles that serve as Ca2+stores in somatic cells. Here, we review i) the evidence for the expression in sperm of the molecular components (pumps and channels) which are functionally significant in the activity of Ca2+stores of somatic cells and ii) the evidence for the existence of functional Ca2+stores in sperm. This evidence supports the existence of at least two storage organelles in mammalian sperm, one in the acrosomal region and another in the region of the sperm neck and midpiece. We then go on to discuss the probable identity of these organelles and their discrete functions: regulation by the acrosome of its own secretion and regulation by membranous organelles at the sperm neck (and possibly by the mitochondria) of flagellar activity and hyperactivation. Finally, we consider the ability of the sperm discretely to control mobilisation of these stores and the functional interaction of stored Ca2+at the sperm neck/midpiece with CatSper channels in the principal piece in regulation of the activities of mammalian sperm.

Sign in / Sign up

Export Citation Format

Share Document