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Jafari A, Mokhtari G, Madani A, Leyli E. Sildenafil citrate effects on seminal parameters in male participants with idiopathic infertility; A randomized, double-blind, controlled cross-over clinical trial study. UROLOGICAL SCIENCE 2022. [DOI: 10.4103/uros.uros_113_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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2
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Abstract
Fertilization, a crucial event for species preservation, in sea urchins, as in many other organisms, requires sperm motility regulation. In Strongylocentrotus purpuratus sea urchins, speract, a sperm chemoattractant component released to seawater from the outer egg layer, attracts sperm after binding to its receptor in the sperm flagellum. Previous experiments performed in demembranated sperm indicated that motility regulation in these cells involved protein phosphorylation mainly due to the cAMP-dependent protein kinase (PKA). However, little information is known about the involvement of protein kinase C (PKC) in this process. In this work, using intact S. purpuratus sea urchin sperm, we show that: (i) the levels of both phosphorylated PKA (PKA substrates) and PKC (PKC substrates) substrates change between immotile, motile and speract-stimulated sperm, and (ii) the non-competitive PKA (H89) and PKC (chelerythrine) inhibitors diminish the circular velocity of sperm and alter the phosphorylation levels of PKA substrates and PKC substrates, while the competitive inhibitors Rp-cAMP and bisindolylmaleimide (BIM) do not. Altogether, our results show that both PKA and PKC participate in sperm motility regulation through a crosstalk in the signalling pathway. These results contribute to a better understanding of the mechanisms that govern motility in sea urchin sperm.
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Priego-Espinosa DA, Darszon A, Guerrero A, González-Cota AL, Nishigaki T, Martínez-Mekler G, Carneiro J. Modular analysis of the control of flagellar Ca2+-spike trains produced by CatSper and CaV channels in sea urchin sperm. PLoS Comput Biol 2020; 16:e1007605. [PMID: 32119665 PMCID: PMC7067495 DOI: 10.1371/journal.pcbi.1007605] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/12/2020] [Accepted: 12/13/2019] [Indexed: 11/18/2022] Open
Abstract
Intracellular calcium ([Ca2+]i) is a basic and ubiquitous cellular signal controlling a wide variety of biological processes. A remarkable example is the steering of sea urchin spermatozoa towards the conspecific egg by a spatially and temporally orchestrated series of [Ca2+]i spikes. Although this process has been an experimental paradigm for reproduction and sperm chemotaxis studies, the composition and regulation of the signalling network underlying the cytosolic calcium fluctuations are hitherto not fully understood. Here, we used a differential equations model of the signalling network to assess which set of channels can explain the characteristic envelope and temporal organisation of the [Ca2+]i-spike trains. The signalling network comprises an initial membrane hyperpolarisation produced by an Upstream module triggered by the egg-released chemoattractant peptide, via receptor activation, cGMP synthesis and decay. Followed by downstream modules leading to intraflagellar pH (pHi), voltage and [Ca2+]i fluctuations. The Upstream module outputs were fitted to kinetic data on cGMP activity and early membrane potential changes measured in bulk cell populations. Two candidate modules featuring voltage-dependent Ca2+-channels link these outputs to the downstream dynamics and can independently explain the typical decaying envelope and the progressive spacing of the spikes. In the first module, [Ca2+]i-spike trains require the concerted action of a classical CaV-like channel and a potassium channel, BK (Slo1), whereas the second module relies on pHi-dependent CatSper dynamics articulated with voltage-dependent neutral sodium-proton exchanger (NHE). We analysed the dynamics of these two modules alone and in mixed scenarios. We show that the [Ca2+]i dynamics observed experimentally after sustained alkalinisation can be reproduced by a model featuring the CatSper and NHE module but not by those including the pH-independent CaV and BK module or proportionate mixed scenarios. We conclude in favour of the module containing CatSper and NHE and highlight experimentally testable predictions that would corroborate this conclusion. Fertilisation in marine invertebrates, such as the sea urchin, occurs during broadcast spawning events in which males and females of co-localised species ejaculate sperm and spawn eggs synchronously. During these events, spermatozoa have to find and fertilise conspecific eggs in the midst of all the other ones, which is a remarkable navigation and mating choice achievement. Sperm cells do this by navigating towards the source of species-specific peptides released by the egg, steered by spatial and temporally orchestrated peaks in intracellular calcium concentration that trigger sudden reorientations. How these calcium spikes are regulated and timed remains elusive. Different calcium channels have been implicated by indirect experimental evidence giving rise to a complex network of putative interacting components. We gained insight into the structure and function of this network by modelling it as a set of candidate modules that could be studied separately. By using this ‘divide and conquer’ approach to the complexity of the network, we could characterise the potential dynamics of each module and confront these dynamics with specific quantitative data. Our results indicate that the channel mediating calcium signals in sea urchin sperm is likely CatSper, a calcium channel necessary for human male fertility.
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Affiliation(s)
| | - Alberto Darszon
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Adán Guerrero
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Ana Laura González-Cota
- Washington University School of Medicine, Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, St. Louis, Missouri, United States of America
| | - Takuya Nishigaki
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Gustavo Martínez-Mekler
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
- Centro de Ciencias de la Complejidad UNAM, CDMX, México
- Laboratoire de Physique Statistique, Départment de Physique, Ecole Normale Supérieure, Paris, France
- * E-mail: (GMM); (JC)
| | - Jorge Carneiro
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- * E-mail: (GMM); (JC)
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4
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Trötschel C, Hamzeh H, Alvarez L, Pascal R, Lavryk F, Bönigk W, Körschen HG, Müller A, Poetsch A, Rennhack A, Gui L, Nicastro D, Strünker T, Seifert R, Kaupp UB. Absolute proteomic quantification reveals design principles of sperm flagellar chemosensation. EMBO J 2020; 39:e102723. [PMID: 31880004 PMCID: PMC7024835 DOI: 10.15252/embj.2019102723] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/19/2019] [Accepted: 11/22/2019] [Indexed: 11/19/2022] Open
Abstract
Cilia serve as cellular antennae that translate sensory information into physiological responses. In the sperm flagellum, a single chemoattractant molecule can trigger a Ca2+ rise that controls motility. The mechanisms underlying such ultra-sensitivity are ill-defined. Here, we determine by mass spectrometry the copy number of nineteen chemosensory signaling proteins in sperm flagella from the sea urchin Arbacia punctulata. Proteins are up to 1,000-fold more abundant than the free cellular messengers cAMP, cGMP, H+ , and Ca2+ . Opto-chemical techniques show that high protein concentrations kinetically compartmentalize the flagellum: Within milliseconds, cGMP is relayed from the receptor guanylate cyclase to a cGMP-gated channel that serves as a perfect chemo-electrical transducer. cGMP is rapidly hydrolyzed, possibly via "substrate channeling" from the channel to the phosphodiesterase PDE5. The channel/PDE5 tandem encodes cGMP turnover rates rather than concentrations. The rate-detection mechanism allows continuous stimulus sampling over a wide dynamic range. The textbook notion of signal amplification-few enzyme molecules process many messenger molecules-does not hold for sperm flagella. Instead, high protein concentrations ascertain messenger detection. Similar mechanisms may occur in other small compartments like primary cilia or dendritic spines.
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Affiliation(s)
- Christian Trötschel
- Fakultät für Biologie und BiotechnologieRuhr‐Universität BochumBochumGermany
| | - Hussein Hamzeh
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
- Marine Biological LaboratoryWoods HoleMAUSA
| | - Luis Alvarez
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
| | - René Pascal
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
| | - Fedir Lavryk
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
| | - Wolfgang Bönigk
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
| | - Heinz G Körschen
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
| | - Astrid Müller
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
| | - Ansgar Poetsch
- Fakultät für Biologie und BiotechnologieRuhr‐Universität BochumBochumGermany
- Present address:
Center for Marine and Molecular BiotechnologyQNLMQindaoChina
- Present address:
College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Andreas Rennhack
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
| | - Long Gui
- Departments of Cell Biology and BiophysicsUniversity of Texas Southwestern Medical CenterDallasTXUSA
| | - Daniela Nicastro
- Departments of Cell Biology and BiophysicsUniversity of Texas Southwestern Medical CenterDallasTXUSA
| | - Timo Strünker
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
- Marine Biological LaboratoryWoods HoleMAUSA
- Center of Reproductive Medicine and AndrologyUniversity Hospital MünsterMünsterGermany
| | - Reinhard Seifert
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
- Marine Biological LaboratoryWoods HoleMAUSA
| | - U Benjamin Kaupp
- Center of Advanced European Studies and Research (caesar), Molecular Sensory SystemsBonnGermany
- Marine Biological LaboratoryWoods HoleMAUSA
- Life& Medical Sciences Institute (LIMES)University of BonnBonnGermany
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5
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Hamzeh H, Alvarez L, Strünker T, Kierzek M, Brenker C, Deal PE, Miller EW, Seifert R, Kaupp UB. Kinetic and photonic techniques to study chemotactic signaling in sea urchin sperm. Methods Cell Biol 2019; 151:487-517. [PMID: 30948028 DOI: 10.1016/bs.mcb.2018.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Sperm from sea urchins are attracted by chemical cues released by the egg-a mechanism called chemotaxis. We describe here the signaling pathway and molecular components endowing sperm with single-molecule sensitivity. Chemotactic signaling and behavioral responses occur on a timescale of a few milliseconds to seconds. We describe the techniques and chemical tools used to resolve the signaling events in time. The techniques include rapid-mixing devices, rapid stroboscopic microscopy, and photolysis of caged second messengers and chemoattractants.
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Affiliation(s)
- Hussein Hamzeh
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), Bonn, Germany
| | - Luis Alvarez
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), Bonn, Germany
| | - Timo Strünker
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Michelina Kierzek
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Christoph Brenker
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Parker E Deal
- Department of Chemistry, University of California, Berkeley, CA, United States
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, CA, United States; Department of Molecular & Cell Biology, University of California, Berkeley, CA, United States; Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States
| | - Reinhard Seifert
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), Bonn, Germany
| | - U Benjamin Kaupp
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), Bonn, Germany.
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6
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Shah MA, Kirkman LM, Sitver PJ, Shelley C. Pharmacological Disruption of Sea Urchin Tube Foot Motility and Behavior. THE BIOLOGICAL BULLETIN 2018; 234:96-105. [PMID: 29856672 DOI: 10.1086/697378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The understanding of the molecular basis of sea urchin behavior and sensory and motor systems lags far behind that of many other animal species. To investigate whole-animal behavior pharmacologically, we first demonstrated that immersion in drug solution is an effective drug administration route for sea urchins, whereas oral drug administration was found to be ineffective. Although intracoelomic injection was found to be effective at administering drugs, it was also found that injection itself can disrupt normal sea urchin behavior. Using the drug immersion procedure, we demonstrate that sea urchin locomotion and the sea urchin righting response are inhibited in a dose-dependent manner by the phosphodiesterase inhibitor theophylline and the transient receptor potential channel inhibitor 2-aminoethoxydiphenyl borate. The sea urchin righting response was also inhibited by the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester and the Ca2+ channel inhibitor diltiazem, which, along with theophylline and 2-aminoethoxydiphenyl borate, would all be expected to disrupt smooth muscle function, based on studies in other animals. In addition, the removal of extracellular Ca2+ also inhibited the righting response, whereas an inhibitor of intracellular Ca2+ release, thapsigargin, did not affect the righting response, indicating that extracellular Ca2+ rather than intracellular Ca2+ stores are required for righting.
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Key Words
- 2-APB, 2-aminoethoxydiphenyl borate
- DMSO, dimethyl sulfoxide
- L-NAME, N(G)-nitro-l-arginine methyl ester
- NO, nitric oxide
- PDE, phosphodiesterase
- SERCA, sarco/endoplasmic reticulum Ca2+-ATPase
- TRP, transient receptor potential
- TRPC, canonical-type TRP
- TRPM, melastatin-type TRP
- TRPV, vanilloid-type TRP
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Iida T, Iwata Y, Mohri T, Baba SA, Hirohashi N. A coordinated sequence of distinct flagellar waveforms enables a sharp flagellar turn mediated by squid sperm pH-taxis. Sci Rep 2017; 7:12938. [PMID: 29021593 PMCID: PMC5636881 DOI: 10.1038/s41598-017-13406-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/22/2017] [Indexed: 11/20/2022] Open
Abstract
Animal spermatozoa navigate by sensing ambient chemicals to reach the site of fertilization. Generally, such chemicals derive from the female reproductive organs or cells. Exceptionally, squid spermatozoa mutually release and perceive carbon dioxide to form clusters after ejaculation. We previously identified the pH-taxis by which each spermatozoon can execute a sharp turn, but how flagellar dynamics enable this movement remains unknown. Here, we show that initiation of the turn motion requires a swim down a steep proton gradient (a theoretical estimation of ≥0.025 pH/s), crossing a threshold pH value of ~5.5. Time-resolved kinematic analysis revealed that the turn sequence results from the rhythmic exercise of two flagellar motions: a stereotypical flagellar ‘bent-cane’ shape followed by asymmetric wave propagation, which enables a sharp turn in the realm of low Reynolds numbers. This turning episode is terminated by an ‘overshoot’ trajectory that differs from either straight-line motility or turning. As with bidirectional pH-taxes in some bacteria, squid spermatozoa also showed repulsion from strong acid conditions with similar flagellar kinematics as in positive pH-taxis. These findings indicate that squid spermatozoa might have a unique reorientation mechanism, which could be dissimilar to that of classical egg-guided sperm chemotaxis in other marine invertebrates.
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Affiliation(s)
- Tomohiro Iida
- Oki Marine Biological Station, Education and Research Center for Biological Resources, Shimane University, 194 Kamo, Okinoshima-cho, Oki, Shimane, 685-0024, Japan
| | - Yoko Iwata
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan
| | - Tatsuma Mohri
- Section of Individual Researches, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji-cho Okazaki, 444-8787, Japan
| | - Shoji A Baba
- Ochanomizu University, 2-2-1 Otsuka, Tokyo, 112-8610, Japan
| | - Noritaka Hirohashi
- Oki Marine Biological Station, Education and Research Center for Biological Resources, Shimane University, 194 Kamo, Okinoshima-cho, Oki, Shimane, 685-0024, Japan.
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8
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Abstract
Fertilization is exceptionally complex and, depending on the species, happens in entirely different environments. External fertilizers in aquatic habitats, like marine invertebrates or fish, release their gametes into the seawater or freshwater, whereas sperm from most internal fertilizers like mammals cross the female genital tract to make their way to the egg. Various chemical and physical cues guide sperm to the egg. Quite generally, these cues enable signaling pathways that ultimately evoke a cellular Ca2+ response that modulates the waveform of the flagellar beat and, hence, the swimming path. To cope with the panoply of challenges to reach and fertilize the egg, sperm from different species have developed their own unique repertoire of signaling molecules and mechanisms. Here, we review the differences and commonalities for sperm sensory signaling in marine invertebrates (sea urchin), fish (zebrafish), and mammals (mouse, human).
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Affiliation(s)
- Dagmar Wachten
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research (caesar), 53175 Bonn, Germany
| | - Jan F Jikeli
- Minerva Max Planck Research Group, Molecular Physiology, Center of Advanced European Studies and Research (caesar), 53175 Bonn, Germany
| | - U Benjamin Kaupp
- Department Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), 53175 Bonn, Germany
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9
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Mohd Zanuri NB, Bentley MG, Caldwell GS. Assessing the impact of diclofenac, ibuprofen and sildenafil citrate (Viagra ®) on the fertilisation biology of broadcast spawning marine invertebrates. MARINE ENVIRONMENTAL RESEARCH 2017; 127:126-136. [PMID: 28410750 DOI: 10.1016/j.marenvres.2017.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 05/22/2023]
Abstract
Exposure to synthetic chemicals is a key environmental challenge faced by aquatic organisms. The time and dose effects of the pharmaceuticals diclofenac, ibuprofen, and sildenafil citrate on sperm motility and successful fertilisation are studied using the echinoderms, Asterias rubens and Psammechinus miliaris, and the polychaete worm Arenicola marina, all important components of the marine benthos. Motility was reduced for all species when exposed to diclofenac concentrations ≥0.1 μg/L. Exposure to ≥1.0 μg/L of ibuprofen affected only P. miliaris gametes and fertilisation success of A. marina. A. rubens and P. miliaris sperm increased in both percentage motility and swimming velocity when exposed to sildenafil citrate at concentrations ≥18 and ≥ 50 ng/L, respectively. Pre-incubation of sperm with sildenafil citrate significantly increased fertilisation success in A. rubens and P. miliaris but not in A. marina. Pre-incubated A. rubens oocytes fertilised successfully in ibuprofen. According to EU Directive 93/67/EEC, diclofenac is classified as a very toxic substance to gametes of A. rubens, P. miliaris, and A. marina (EC50 = 100-1000 μg/L) while ibuprofen is classified as very toxic to gametes of P. miliaris but non-toxic to gametes of A. marina (EC50 > 10,000 μg/L). The present study indicates that diclofenac exposure may have negative impacts on invertebrate reproductive success, whereas ibuprofen potentially may compromise P. miliaris reproduction. This study provides a valuable insight into the mechanisms that allow marine invertebrates to survive and reproduce in contaminated and changing habitats.
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Affiliation(s)
- Norlaila Binti Mohd Zanuri
- School of Marine Science and Technology, Newcastle University, Ridley Building, Claremont Road, Newcastle upon Tyne, NE1 7RU, UK
| | - Matthew G Bentley
- School of Marine Science and Technology, Newcastle University, Ridley Building, Claremont Road, Newcastle upon Tyne, NE1 7RU, UK
| | - Gary S Caldwell
- School of Marine Science and Technology, Newcastle University, Ridley Building, Claremont Road, Newcastle upon Tyne, NE1 7RU, UK.
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10
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11
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Strünker T, Alvarez L, Kaupp UB. At the physical limit - chemosensation in sperm. Curr Opin Neurobiol 2015; 34:110-6. [PMID: 25768273 DOI: 10.1016/j.conb.2015.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 02/18/2015] [Accepted: 02/18/2015] [Indexed: 12/15/2022]
Abstract
Many cells probe their environment for chemical cues. Some cells respond to picomolar concentrations of neuropeptides, hormones, pheromones, or chemoattractants. At such low concentrations, cells encounter only a few molecules. The mechanistic underpinnings of single-molecule sensitivity are not known for any eukaryotic cell. Sea urchin sperm offer a unique model to unveil in quantitative terms the principles underlying chemosensation at the physical limit. Here, we discuss the mechanisms of such exquisite sensitivity and the computational operations performed by sperm during chemotactic steering. Moreover, we highlight commonalities and differences between signalling in sperm and photoreceptors and among sperm from different species.
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Affiliation(s)
- T Strünker
- Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, Bonn 53175, Germany
| | - L Alvarez
- Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, Bonn 53175, Germany
| | - U B Kaupp
- Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, Bonn 53175, Germany.
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12
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Identification of putative fertility markers in seminal plasma of crossbred bulls through differential proteomics. Theriogenology 2014; 82:1254-62.e1. [DOI: 10.1016/j.theriogenology.2014.08.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/07/2014] [Accepted: 08/08/2014] [Indexed: 12/30/2022]
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13
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Nishigaki T, José O, González-Cota AL, Romero F, Treviño CL, Darszon A. Intracellular pH in sperm physiology. Biochem Biophys Res Commun 2014; 450:1149-58. [PMID: 24887564 PMCID: PMC4146485 DOI: 10.1016/j.bbrc.2014.05.100] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 05/22/2014] [Indexed: 10/25/2022]
Abstract
Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction.
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Affiliation(s)
- Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Omar José
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Ana Laura González-Cota
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Francisco Romero
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Claudia L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico.
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14
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Vacquier VD, Loza-Huerta A, García-Rincón J, Darszon A, Beltrán C. Soluble adenylyl cyclase of sea urchin spermatozoa. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2621-8. [PMID: 25064590 DOI: 10.1016/j.bbadis.2014.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 07/07/2014] [Accepted: 07/15/2014] [Indexed: 02/05/2023]
Abstract
Fertilization, a key step in sexual reproduction, requires orchestrated changes in cAMP concentrations. It is notable that spermatozoa (sperm) are among the cell types with extremely high adenylyl cyclase (AC) activity. As production and consumption of this second messenger need to be locally regulated, the discovery of soluble AC (sAC) has broadened our understanding of how such cells deal with these requirements. In addition, because sAC is directly regulated by HCO(3)(-) it is able to translate CO₂/HCO(3)(-)/pH changes into cAMP levels. Fundamental sperm functions such as maturation, motility regulation and the acrosome reaction are influenced by cAMP; this is especially true for sperm of the sea urchin (SU), an organism that has been a model in the study of fertilization for more than 130 years. Here we summarize the discovery and properties of SU sperm sAC, and discuss its involvement in sperm physiology. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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Affiliation(s)
- Victor D Vacquier
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0202, USA.
| | - Arlet Loza-Huerta
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Distrito Federal 04510, Mexico.
| | - Juan García-Rincón
- Departamento de Genética del Desarrollo y Fisiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico.
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico.
| | - Carmen Beltrán
- Departamento de Genética del Desarrollo y Fisiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico.
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15
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Jankowska A, Sharma RK, Duda T. Ca(2+)-modulated ROS-GC1 transduction system in testes and its presence in the spermatogenic cells. Front Mol Neurosci 2014; 7:34. [PMID: 24808824 PMCID: PMC4010774 DOI: 10.3389/fnmol.2014.00034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 04/08/2014] [Indexed: 11/21/2022] Open
Abstract
ROS-GC1 belongs to the Ca2+-modulated sub-family of membrane guanylate cyclases. It primarily exists and is linked with signaling of the sensory neurons – sight, smell, taste, and pinealocytes. Exceptionally, it is also present and is Ca2+-modulated in t he non-neuronal cells, the sperm cells in the testes, where S100B protein serves as its Ca2+ sensor. The present report demonstrates the identification of an additional Ca2+ sensor of ROS-GC1 in the testes, neurocalcin δ. Through mouse molecular genetic models, it compares and quantifies the relative input of the S100B and neurocalcin δ in regulating the Ca2+ signaling of ROS-GC1 transduction machinery, and via immunochemistry it demonstrates the co-presence of neurocalcin δ and ROS-GC1 in the spermatogenic cells of the testes. The suggestion is that in more ways than one the Ca2+-modulated ROS-GC1 transduction system is linked with the testicular function. This non-neuronal transduction system may represent an illustration of the ROS-GC1 expanding role in the trans-signaling of the neural and non-neural systems.
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Affiliation(s)
- Anna Jankowska
- The Unit of Molecular Biology, Department of Cell Biology, Poznan University of Medical Sciences Poznan, Poland
| | - Rameshwar K Sharma
- The Unit of Regulatory and Molecular Biology, Research Divisions of Biochemistry and Molecular Biology Salus University PA, USA
| | - Teresa Duda
- The Unit of Regulatory and Molecular Biology, Research Divisions of Biochemistry and Molecular Biology Salus University PA, USA
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Alvarez L, Friedrich BM, Gompper G, Kaupp UB. The computational sperm cell. Trends Cell Biol 2013; 24:198-207. [PMID: 24342435 DOI: 10.1016/j.tcb.2013.10.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 10/13/2013] [Accepted: 10/14/2013] [Indexed: 10/25/2022]
Abstract
Sperm are guided to the egg by a gradient of chemical attractants - a process called chemotaxis. The binding of the chemoattractant to receptors on the surface of the flagellum triggers a cascade of signaling events that eventually lead to an influx of Ca(2+) ions. Based on these Ca(2+) surges, which control the waveform of the flagellar beat, sperm adjust their swimming path toward the egg. In past years, many components of chemotactic signaling have been identified. Moreover, kinetic spectroscopy and imaging techniques unraveled the sequence of cellular events controlling swimming behavior. During navigation in a chemical gradient, sperm perform a surprising variety of computational operations. Here we discuss theoretical concepts of navigation strategies and the cellular underpinnings.
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Affiliation(s)
- Luis Alvarez
- Center of Advanced European Studies and Research (CAESAR), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
| | - Benjamin M Friedrich
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - Gerhard Gompper
- Research Centre Jülich, Institute of Complex Systems (ICS-2), 52425 Jülich, Germany
| | - U Benjamin Kaupp
- Center of Advanced European Studies and Research (CAESAR), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
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17
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Loza-Huerta A, Vera-Estrella R, Darszon A, Beltrán C. Certain Strongylocentrotus purpuratus sperm mitochondrial proteins co-purify with low density detergent-insoluble membranes and are PKA or PKC-substrates possibly involved in sperm motility regulation. Biochim Biophys Acta Gen Subj 2013; 1830:5305-15. [DOI: 10.1016/j.bbagen.2013.07.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 06/24/2013] [Accepted: 07/27/2013] [Indexed: 12/14/2022]
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Affiliation(s)
- U B Kaupp
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, 53175 Bonn, Germany
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19
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Aguilera LU, Galindo BE, Sánchez D, Santillán M. What is the core oscillator in the speract-activated pathway of the Strongylocentrotus purpuratus sperm flagellum? Biophys J 2012; 102:2481-8. [PMID: 22713563 DOI: 10.1016/j.bpj.2012.03.075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 03/06/2012] [Accepted: 03/29/2012] [Indexed: 12/31/2022] Open
Abstract
Sperm chemotaxis has an important role in fertilization. Most of our knowledge regarding this phenomenon comes from studies in organisms whose fertilization occurs externally, like sea urchins. Sea urchin spermatozoa respond to sperm-activating peptides, which diffuse from the egg jelly coat and interact with their receptor in the flagellum, triggering several physiological responses: changes in membrane potential, intracellular pH, cyclic nucleotide levels, and intracellular Ca2+ concentration ([Ca2+]). In particular, flagellar [Ca2+] has been shown to oscillate. These [Ca2+] oscillations are correlated with changes in the flagellar shape and so with the regulation of the sperm swimming paths. In this study, we demonstrate, from a mathematical modeling perspective, that the reported speract-activated signaling pathway in Strongylocentrotus purpuratus (speract being a sperm-activating peptide specific to this species) has the necessary elements to replicate the reported [Ca2+] oscillations. We further investigate which elements of this signaling pathway constitute the core oscillator.
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Affiliation(s)
- Luis U Aguilera
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Monterrey, Parque de Investigación e Innovación Tecnológica, Apodaca, Mexico
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20
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Darszon A, Nishigaki T, Beltran C, Treviño CL. Calcium Channels in the Development, Maturation, and Function of Spermatozoa. Physiol Rev 2011; 91:1305-55. [DOI: 10.1152/physrev.00028.2010] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A proper dialogue between spermatozoa and the egg is essential for conception of a new individual in sexually reproducing animals. Ca2+ is crucial in orchestrating this unique event leading to a new life. No wonder that nature has devised different Ca2+-permeable channels and located them at distinct sites in spermatozoa so that they can help fertilize the egg. New tools to study sperm ionic currents, and image intracellular Ca2+ with better spatial and temporal resolution even in swimming spermatozoa, are revealing how sperm ion channels participate in fertilization. This review critically examines the involvement of Ca2+ channels in multiple signaling processes needed for spermatozoa to mature, travel towards the egg, and fertilize it. Remarkably, these tiny specialized cells can express exclusive channels like CatSper for Ca2+ and SLO3 for K+, which are attractive targets for contraception and for the discovery of novel signaling complexes. Learning more about fertilization is a matter of capital importance; societies face growing pressure to counteract rising male infertility rates, provide safe male gamete-based contraceptives, and preserve biodiversity through improved captive breeding and assisted conception initiatives.
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Affiliation(s)
- Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Carmen Beltran
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Claudia L. Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
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Dimitriadis F, Tsambalas S, Tsounapi P, Kawamura H, Vlachopoulou E, Haliasos N, Gratsias S, Watanabe T, Saito M, Miyagawa I, Sofikitis N. Effects of phosphodiesterase-5 inhibitors on Leydig cell secretory function in oligoasthenospermic infertile men: a randomized trial. BJU Int 2011; 106:1181-5. [PMID: 20184572 DOI: 10.1111/j.1464-410x.2010.09243.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE to evaluate the effects of phosphodiesterase-5 inhibitors (PDE5-i) on Leydig cell secretory function (LCSF). PATIENTS AND METHODS in all, 75 men with oligoasthenospermia were treated daily for 12 weeks with either vardenafil (23 men, group A), sildenafil (25 men, group B) or l-carnitine (26 men, group C); a further group of 22 men with oligoasthenospermia (group D) received no treatment. Serum levels of insulin-like-3 peptide (INSL3) were evaluated before and after the end of the treatment in each of groups A, B and C, respectively. Serum INSL3 levels were measured in each participant of group D before and after the 12-week experimental period. RESULTS within group A and B, the peripheral serum mean INSL3 concentration, sperm concentration, percentage of motile spermatozoa, and percentage of morphologically normal spermatozoa were significantly greater after PDE5-i treatment than before. CONCLUSION we suggest that PDE5-i enhances LCSF, as the mean INSL3 concentration was significantly greater after PDE5-i administration than before, within groups A and B. This enhancement in LCSF might contribute to the increase in sperm concentration and sperm motility after administration of PDE5-i.
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Affiliation(s)
- Fotios Dimitriadis
- Department of Urology, Tottori University School of Medicine, Yonago, Japan
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Castro MO, Pomin VH, Santos LL, Vilela-Silva ACES, Hirohashi N, Pol-Fachin L, Verli H, Mourão PAS. A unique 2-sulfated {beta}-galactan from the egg jelly of the sea urchin Glyptocidaris crenularis: conformation flexibility versus induction of the sperm acrosome reaction. J Biol Chem 2009; 284:18790-800. [PMID: 19403528 DOI: 10.1074/jbc.m109.005702] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sulfated polysaccharides from the egg jelly of sea urchins act as species-specific inducers of the sperm acrosome reaction, which is a rare molecular mechanism of carbohydrate-induced signal-transduction event in animal cells. The sea urchin polysaccharides differ in monosaccharide composition (l-fucose or l-galactose), glycosylation, and sulfation sites, but they are always in the alpha-anomeric configuration. Herein, structural analysis of the polysaccharide from the sea urchin Glyptocidaris crenularis surprisingly revealed a unique sulfated beta-d-galactan composed by (3-beta-d-Galp-2(OSO(3))-1-->3-beta-d-Galp-1)(n) repeating units. Subsequently, we used the G. crenularis galactan to compare different 2-sulfated polysaccharides as inducers of the acrosome reaction using homologous and heterologous sperm. We also tested the effect of chemically over-sulfated galactans. Intriguingly, the anomeric configuration of the glycosidic linkage rather than the monosaccharide composition (galactose or fucose) is the preferential structural requirement for the effect of these polysaccharides on sea urchin fertilization. Nuclear magnetic resonance and molecular dynamics indicate that sulfated alpha-galactan or alpha-fucan have less dynamic structural behavior, exhibiting fewer conformational populations, with an almost exclusive conformational state with glycosidic dihedral angles Phi/Psi = -102 degrees /131 degrees . The preponderant conformer observed in the sulfated alpha-galactan or alpha-fucan is not observed among populations in the beta-form despite its more flexible structure in solution. Possibly, a proper spatial arrangement is required for interaction of the sea urchin-sulfated polysaccharides with the specific sperm receptor.
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Affiliation(s)
- Michelle O Castro
- Laboratório de Tecido Conjuntivo, Hospital Universitário Clementino Fraga Filho, Brazil
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Regulation of a Drosophila melanogaster cGMP-specific phosphodiesterase by prenylation and interaction with a prenyl-binding protein. Biochem J 2008; 414:363-74. [PMID: 18503409 DOI: 10.1042/bj20080560] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Post-translational modification by isoprenylation is a pivotal process for the correct functioning of many signalling proteins. The Drosophila melanogaster cGMP-PDE (cGMP-specific phosphodiesterase) DmPDE5/6 possesses a CaaX-box prenylation signal motif, as do several novel cGMP-PDEs from insect and echinoid species (in CaaX, C is cysteine, a is an aliphatic amino acid and X is 'any' amino acid). DmPDE5/6 is prenylated in vivo at Cys(1128) and is localized to the plasma membrane when expressed in Drosophila S2 cells. Site-directed mutagenesis of the prenylated cysteine residue (C1128S-DmPDE5/6), pharmacological inhibition of prenylation or co-expression of DmPrBP (Drosophila prenyl-binding protein)/delta each alters the subcellular localization of DmPDE5/6. Thus prenylation constitutes a critical post-translational modification of DmPDE5/6 for membrane targeting. Co-immunoprecipitation and subcellular-fractionation experiments have shown that DmPDE5/6 interacts with DmPrBP/delta in Drosophila S2 cells. Transgenic lines allow targeted expression of tagged prenylation-deficient C1128S-DmPDE5/6 in Type I (principal) cells in Drosophila Malpighian tubules, an in vivo model for DmPDE5/6 function. In contrast with wild-type DmPDE5/6, which was exclusively associated with the apical membrane, the C1128S-DmPDE5/6 mutant form was located primarily in the cytosol, although some residual association occurred at the apical membrane. Despite the profound change in intracellular localization of C1128S-DmPDE5/6, active transport of cGMP is affected in the same way as it is by DmPDE5/6. This suggests that, in addition to prenylation and interaction with DmPrBP/delta, further functional membrane-targeting signals exist within DmPDE5/6.
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Dimitriadis F, Giannakis D, Pardalidis N, Zikopoulos K, Paraskevaidis E, Giotitsas N, Kalaboki V, Tsounapi P, Baltogiannis D, Georgiou I, Saito M, Watanabe T, Miyagawa I, Sofikitis N. Effects of phosphodiesterase-5 inhibitors on sperm parameters and fertilizing capacity. Asian J Androl 2008; 10:115-33. [PMID: 18087651 DOI: 10.1111/j.1745-7262.2008.00373.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The aim of this review study is to elucidate the effects that phosphodiesterase 5 (PDE5) inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase (AC) system and the cGMP/guanylate cyclase (GC) system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide (NO) leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil's actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the improvement of the outcome of assisted reproductive technology (ART) programs. In the future PDE5 inhibitors might serve as adjunct therapeutical agents for the alleviation of male infertility.
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Affiliation(s)
- F Dimitriadis
- Department of Urology, Ioannina University School of Medicine, Ioannina 45110, Greece
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25
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Pomara G, Morelli G, Canale D, Turchi P, Caglieresi C, Moschini C, Liguori G, Selli C, Macchia E, Martino E, Francesca F. Alterations in sperm motility after acute oral administration of sildenafil or tadalafil in young, infertile men. Fertil Steril 2007; 88:860-5. [PMID: 17544419 DOI: 10.1016/j.fertnstert.2006.12.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2006] [Revised: 12/22/2006] [Accepted: 12/22/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To evaluate the acute effect of sildenafil and tadalafil on seminal parameters in young, infertile patients. DESIGN Prospective, randomized, double-blind, crossover clinical investigation on semen parameters after the administration of a single dose of sildenafil (50 mg) or tadalafil (20 mg). SETTING An academic hospital as well as a male infertility center and clinical andrology laboratories. PATIENT(S) Eighteen young, infertile men. INTERVENTION(S) Oral administration of a single dose of sildenafil (50 mg) or tadalafil (20 mg) in a blind, randomized order. The semen samples were collected 1 or 2 hours after each treatment. MAIN OUTCOME MEASURE(S) Changes in sperm parameters after sildenafil and tadalafil administration, compared with the basal conditions. RESULT(S) A significant increase in sperm progressive motility (median value, 37.0% vs. 28.5%) was observed after sildenafil administration as compared with baseline; in contrast, a significant decreased value was observed after tadalafil (median value, 21.5% vs. 28.5%). CONCLUSION(S) These preliminary results indicate that sperm motility appears to be acutely affected in young, infertile patients by a single dose of sildenafil and tadalafil, with opposite effects: stimulatory by the former and inhibitory by the latter.
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Affiliation(s)
- Giorgio Pomara
- Urology Unit, Azienda Ospedaliera Pisana, University of Pisa, Pisa, Italy.
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Nomura M, Vacquier VD. Proteins associated with soluble adenylyl cyclase in sea urchin sperm flagella. ACTA ACUST UNITED AC 2006; 63:582-90. [PMID: 16847896 DOI: 10.1002/cm.20147] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Adenylyl cyclases (ACs) synthesize cAMP and are present in cells as transmembrane AC and soluble AC (sAC). In sperm, the cAMP produced regulates ion channels and it also activates protein kinase-A that in turn phosphorylates specific axonemal proteins to activate flagellar motility. In mammalian sperm, sAC localizes to the midpiece of flagella, whereas in sea urchin sperm sAC is along the entire flagellum. Here we show that in sea urchin sperm, sAC is complexed with proteins of the plasma membrane and axoneme. Immunoprecipitation shows that a minimum of 10 proteins is tightly associated with sAC. Mass spectrometry of peptides derived from these proteins shows them to be: axonemal dynein heavy chains 7 and 9, sperm specific Na+/H+ exchanger, cyclic nucleotide-gated ion channel, sperm specific creatine kinase, membrane bound guanylyl cyclase, cyclic GMP specific phosphodiesterase 5A, the receptor for the egg peptide speract, and alpha- and beta-tubulins. The sAC-associated proteins could be important in linking membrane signal transduction to energy utilisation in the regulation of flagellar motility.
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Affiliation(s)
- Mamoru Nomura
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093-0202, USA.
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