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Ahmed H, Ijaz MU, Riaz M, Jahan S. Sulforaphane inclusion in a freezing medium augments post-thaw motility, functional and biochemical features, and fertility potential of buffalo (Bubalus bubalis) spermatozoa. Res Vet Sci 2023; 158:196-202. [PMID: 37030095 DOI: 10.1016/j.rvsc.2023.03.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/09/2023] [Accepted: 03/27/2023] [Indexed: 04/10/2023]
Abstract
Sulforaphane is a natural and highly effective antioxidant safeguarding the reproductive system, and alleviate oxidative stress. This study was designed in order to elaborate L-sulforaphane effect on semen quality, biochemical parameters, and fertility of buffalo (Bubalus bubalis) spermatozoa. Semen was collected from five buffalo bull with artificial vagina (42 °C) three times and evaluated for volume, consistency (color), motility, and sperm concentration. After critical examination, semen was diluted (50 × 106 spermatozoa per ml, 37 °C) in extenders with (2 μM, 5 μM, 10 μM, and, 20 μM) or without (control) sulforaphane, cooled (from 37 to 4 °C), equilibrated (4 °C), filled (straws, 4 °C), and cryopreserved (LN2, -196 °C). Data analysis exhibited that sulforaphane addition in extender augments total motility (%, 10 μM, and 20 μM than control), progressive motility (%), and rapid velocity (%, 20 μM than control), and velocity parameters (average path velocity, μm/s, straight line velocity, μm/s and curved linear velocity, μm/s, 20 μM than control, and 2 μM). Moreover, sulforaphane augments functional features (membrane functionality, mitochondrial potential, and acrosome integrity) of buffalo sperm (20 μM than control). Sulforaphane preserves biochemical features of seminal plasma of buffalo i.e., Calcium (μM), and total antioxidant capacity (μM/L), followed by reduction in lactate dehydrogenase (IU/L), reactive oxygen species (104 RLU/20 min/ 25 million), and lipid peroxidation (μM/ml) in 20 μM than control. Lastly, sulforaphane augments fertility rate of buffalo sperm at 20 μM than control, and 2 μM. Conclusively the existing study revealed that adding L-sulforaphane (20 μM) in a freezing medium augments motilities, kinematics, functional parameters, and fertility rate of buffalo spermatozoa. Correspondingly, sperm favorable biochemical features were also augmented with sulforaphane followed by reduction in oxidative stress parameters. Further studies are highly recommended to define the particular mechanism of action of sulforaphane in augmenting buffalo post-thawed semen quality, and in vitro fertility potential.
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Affiliation(s)
- Hussain Ahmed
- Department of Zoology, University of Buner, Khyber Pakhtunkhwa (KP), Pakistan; Department of Animal Sciences, Reproductive Physiology Laboratory, Quaid-i-Azam University, Campus, Islamabad, Pakistan.
| | - Muhammad Umar Ijaz
- Department of Zoology, Wildlife and Fisheries, University of Agriculture, Faisalabad, Pakistan
| | - Mehreen Riaz
- Department of Zoology, Women University Swabi, Khyber Pakhtunkhwa, Pakistan
| | - Sarwat Jahan
- Department of Animal Sciences, Reproductive Physiology Laboratory, Quaid-i-Azam University, Campus, Islamabad, Pakistan
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Sánchez González SR, Mata Martínez E, Torres Juárez JA, Arias RJ, De Blas GA, Sánchez Tusie AA. Cortisol modulates Ca 2+ signaling and acrosome reaction in human sperm. Andrology 2023; 11:134-142. [PMID: 36251513 DOI: 10.1111/andr.13319] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 09/22/2022] [Accepted: 10/08/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Stress and elevated cortisol levels have negative effects on fertility, although there is controversy about the effect of cortisol on human sperm. One study reported that hydrocortisone (HC), the synthetic form of cortisol, does not activate CatSper channel but is able to inhibit its activation by progesterone (Pg). However, subsequent reports showed that HC has an agonist effect on CatSper, producing intracellular Ca2+ ([Ca2+ ]i ) increases. These studies were performed using only electrophysiological techniques and fluorometric measurements of Ca2+ . Therefore, it is important to evaluate the effects of different HC concentrations on human sperm physiology using other approaches and techniques. OBJECTIVE To analyze the effects of different HC concentrations on human sperm physiology and to evaluate the association of perceived stress, anxiety and depression with acrosome reaction (AR), and semen quality. MATERIALS AND METHODS In capacitated human sperm, we tested the effects of HC on [Ca2+ ]i mobilization and AR. Furthermore, the perceived stress and symptoms of anxiety and depression were evaluated with standardized psychometric tests. RESULTS HC induces a low increase in [Ca2+ ]i compared to Pg response while, at higher concentrations, HC inhibits the Pg-induced Ca2+ response. Also, low concentrations of HC induce AR and when co-incubating it with Pg, the percentages of AR are decreased. Finally, the anxiety symptoms are negatively correlated with Pg induced AR and semen quality. DISCUSSION HC has an agonist effect on [Ca2+ ]i mobilization and AR. However, our data also suggest that HC may compete for the binding site of Pg. Additionally, the association between anxiety and decreased AR could be explained by high cortisol levels. CONCLUSION Our data showed that HC interferes with the Pg action. Therefore, the negative correlation between anxiety symptoms and Pg-induced AR is due to the accompanying high cortisol levels of this condition and its competitive action with Pg.
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Affiliation(s)
- Sheini Ruturi Sánchez González
- Laboratorio de Biomedicina Celular y Molecular, Centro de Investigación Biomédica Avanzada, Facultad de Medicina, Universidad Autónoma de Querétaro, Santiago de Querétaro, México
| | - Esperanza Mata Martínez
- Instituto de Histología y Embriología Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina
| | - Jorge Arturo Torres Juárez
- Laboratorio de Biomedicina Celular y Molecular, Centro de Investigación Biomédica Avanzada, Facultad de Medicina, Universidad Autónoma de Querétaro, Santiago de Querétaro, México
| | - Rodolfo José Arias
- Instituto de Histología y Embriología Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina
| | - Gerardo Andrés De Blas
- Instituto de Histología y Embriología Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina.,Laboratorio de Teleanálisis e Investigación Traslacional, Área Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Ana Alicia Sánchez Tusie
- Laboratorio de Biomedicina Celular y Molecular, Centro de Investigación Biomédica Avanzada, Facultad de Medicina, Universidad Autónoma de Querétaro, Santiago de Querétaro, México
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Lagares MDA, da Silva GC, Cortes SF, Moreira FHM, Neves FCD, Alves NDC, Viegas RN, Diniz TF, Lemos VS, de Rezende ASC, Freitas MM, Stahlberg R, Nicolino RR. L-carnitine added to post-thawed semen acts as an antioxidant and a stimulator of equine sperm metabolism. Andrologia 2021; 54:e14338. [PMID: 34878673 DOI: 10.1111/and.14338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 11/09/2021] [Accepted: 11/22/2021] [Indexed: 11/27/2022] Open
Abstract
The objective of this study was to enhance the in vitro sperm quality and in vivo fertility of frozen-thawed equine semen by the addition of l-carnitine (LC) to post-thawed semen. Different concentrations of LC were added to thawed samples to obtain four treatments control and 0.5, 1 and 2 mM LC. In the in vitro experiments, sperm motility and kinematics, membrane integrity and intracellular calcium ion concentration ([Ca2+ ]i ) were investigated, and the antioxidant bioactivity of LC was assessed by measuring hydrogen peroxide and nitrite concentrations (NO2 - ). The fertility rate was assessed via the artificial insemination of mares. The treatment with 1 mM LC increased sperm [Ca2+ ]i (60.6 ± 0.05 AU), reduced nitrite concentration (39.1 ± 14.9 µM/µg protein), increased the sperm straightness percentage (STR: 78.3 ± 5.3%) and increased the pregnancy rate (75%) as compared to the control ([Ca2+ ]i 48.4 ± 0.05 AU, NO2 - concentration 63.1 ± 14.4 µM/µg protein, STR 67.5 ± 7.9%, 12.5% pregnancy rate, p < 0.05). These results suggest that 1 mM LC acts as an antioxidant and stimulator of sperm metabolism in post-thawed equine semen, increasing the fertility rate. Thus, addition of LC might be an alternative to improve the fertility of poor quality post-thawed equine semen.
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Affiliation(s)
| | | | - Steyner Franca Cortes
- Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | | | | | | | - Rodrigo Novaes Viegas
- Veterinary School, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Thiago Frederico Diniz
- Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Virginia Soares Lemos
- Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | | | - Marina Morra Freitas
- Veterinary School, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Rubens Stahlberg
- Faculty of Veterinary Medicine, Pontifical Catholic University (PUC- Minas) of Minas Gerais, Betim, Brazil
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Balestrini PA, Sanchez-Cardenas C, Luque GM, Baro Graf C, Sierra JM, Hernández-Cruz A, Visconti PE, Krapf D, Darszon A, Buffone MG. Membrane hyperpolarization abolishes calcium oscillations that prevent induced acrosomal exocytosis in human sperm. FASEB J 2021; 35:e21478. [PMID: 33991146 DOI: 10.1096/fj.202002333rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/14/2022]
Abstract
Sperm capacitation is essential to gain fertilizing capacity. During this process, a series of biochemical and physiological modifications occur that allow sperm to undergo acrosomal exocytosis (AE). At the molecular level, hyperpolarization of the sperm membrane potential (Em) takes place during capacitation. This study shows that human sperm incubated under conditions that do not support capacitation (NC) can become ready for an agonist stimulated AE by pharmacologically inducing Em hyperpolarization with Valinomycin or Amiloride. To investigate how Em hyperpolarization promotes human sperm's ability to undergo AE, live single-cell imaging experiments were performed to simultaneously monitor changes in [Ca2+ ]i and the occurrence of AE. Em hyperpolarization turned [Ca2+ ]i dynamics in NC sperm from spontaneously oscillating into a sustained slow [Ca2+ ]i increase. The addition of progesterone (P4) or K+ to Valinomycin-treated sperm promoted that a significant number of cells displayed a transitory rise in [Ca2+ ]i which then underwent AE. Altogether, our results demonstrate that Em hyperpolarization is necessary and sufficient to prepare human sperm for the AE. Furthermore, this Em change decreased Ca2+ oscillations that block the occurrence of AE, providing strong experimental evidence of the molecular mechanism that drives the acquisition of acrosomal responsiveness.
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Affiliation(s)
- Paula A Balestrini
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Claudia Sanchez-Cardenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, México
| | - Guillermina M Luque
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Carolina Baro Graf
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM) Ciudad Universitaria, Ciudad de México, México
| | - Jessica M Sierra
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Arturo Hernández-Cruz
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM) Ciudad Universitaria, Ciudad de México, México
| | - Pablo E Visconti
- Department of Veterinary and Animal Science, Paige Labs, University of Massachusetts, Amherst, MA, USA
| | - Dario Krapf
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Rosario, Argentina
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, México
| | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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Aldana A, Carneiro J, Martínez-Mekler G, Darszon A. Discrete Dynamic Model of the Mammalian Sperm Acrosome Reaction: The Influence of Acrosomal pH and Physiological Heterogeneity. Front Physiol 2021; 12:682790. [PMID: 34349664 PMCID: PMC8328089 DOI: 10.3389/fphys.2021.682790] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/28/2021] [Indexed: 01/31/2023] Open
Abstract
The acrosome reaction (AR) is an exocytotic process essential for mammalian fertilization. It involves diverse physiological changes (biochemical, biophysical, and morphological) that culminate in the release of the acrosomal content to the extracellular medium as well as a reorganization of the plasma membrane (PM) that allows sperm to interact and fuse with the egg. In spite of many efforts, there are still important pending questions regarding the molecular mechanism regulating the AR. Particularly, the contribution of acrosomal alkalinization to AR triggering physiological conditions is not well understood. Also, the dependence of the proportion of sperm capable of undergoing AR on the physiological heterogeneity within a sperm population has not been studied. Here, we present a discrete mathematical model for the human sperm AR based on the physiological interactions among some of the main components of this complex exocytotic process. We show that this model can qualitatively reproduce diverse experimental results, and that it can be used to analyze how acrosomal pH (pH a ) and cell heterogeneity regulate AR. Our results confirm that a pH a increase can on its own trigger AR in a subpopulation of sperm, and furthermore, it indicates that this is a necessary step to trigger acrosomal exocytosis through progesterone, a known natural inducer of AR. Most importantly, we show that the proportion of sperm undergoing AR is directly related to the detailed structure of the population physiological heterogeneity.
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Affiliation(s)
- Andrés Aldana
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Jorge Carneiro
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova, Oeiras, Portugal
| | - Gustavo Martínez-Mekler
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Shan MM, Sun SC. The multiple roles of RAB GTPases in female and male meiosis. Hum Reprod Update 2021; 27:1013-1029. [PMID: 34227671 DOI: 10.1093/humupd/dmab019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/06/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND RAB GTPases constitute the largest family of small GTPases and are found in all eukaryotes. RAB GTPases regulate components of the endomembrane system, the nucleus and the plasma membrane, and are involved in intracellular actin/tubulin-dependent vesicle movement, membrane fusion and cell growth in mitosis. OBJECTIVE AND RATIONALE RAB GTPases play multiple critical roles during both female and male meiosis. This review summarizes the progress made in our understanding of the role of RAB GTPases in female and male meiosis in different species. We also discuss the potential relationship between RAB GTPases and oocyte/sperm quality, which may help in understanding the mechanisms underlying oogenesis and spermatogenesis and potential genetic causes of infertility. SEARCH METHODS The PubMed database was searched for articles published between 1991 and 2020 using the following terms: 'RAB', 'RAB oocyte', 'RAB sperm' and 'RAB meiosis'. OUTCOMES An analysis of 126 relevant articles indicated that RAB GTPases are present in all eukaryotes, and ten subfamilies (almost 70 members) are expressed in human cells. The roles of 25 RAB proteins and orthologues in female meiosis and 12 in male meiosis have been reported. RAB proteins are essential for the accurate continuity of genetic material, successful fertilization and the normal growth of offspring. Distinct and crucial functions of RAB GTPases in meiosis have been reported. In oocytes, RAB GTPases are involved in spindle organization, kinetochore-microtubule attachment, chromosome alignment, actin filament-mediated spindle migration, cytokinesis, cell cycle and oocyte-embryo transition. RAB GTPases function in mitochondrial processes and Golgi-mediated vesicular transport during female meiosis, and are critical for cortical granule transport during fertilization and oocyte-embryo transition. In sperm, RAB GTPases are vital for cytoskeletal organization and successful cytokinesis, and are associated with Golgi-mediated acrosome formation, membrane trafficking and morphological changes of sperm cells, as well as the exocytosis-related acrosome reaction and zona reaction during fertilization. WIDER IMPLICATIONS Abnormal expression of RAB GTPases disrupts intracellular systems, which may induce diverse diseases. The roles of RAB proteins in female and male reproductive systems, thus, need to be considered. The mechanisms underlying the function of RAB GTPases and the binding specificity of their effectors during oogenesis, spermatogenesis and fertilization remain to be studied. This review should contribute to our understanding of the molecular mechanisms of oogenesis and spermatogenesis and potential genetic causes of infertility.
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Affiliation(s)
- Meng-Meng Shan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
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Zhang L, Qin Z, Sharmin F, Lin W, Ricke KM, Zasloff MA, Stewart AFR, Chen HH. Tyrosine phosphatase PTP1B impairs presynaptic NMDA receptor-mediated plasticity in a mouse model of Alzheimer's disease. Neurobiol Dis 2021; 156:105402. [PMID: 34044147 DOI: 10.1016/j.nbd.2021.105402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/29/2021] [Accepted: 05/21/2021] [Indexed: 12/11/2022] Open
Abstract
Mutations in the beta-amyloid protein (APP) cause familial Alzheimer's disease. In hAPP-J20 mice expressing mutant APP, pharmacological inhibition or genetic ablation of the tyrosine phosphatase PTP1B prevents CA3 hippocampus neuron loss and cognitive decline. However, how targeting PTP1B affects the cellular mechanisms underlying these cognitive deficits remains unknown. Changes in synaptic strength at the hippocampus can affect information processing for learning and memory. While prior studies have focused on post-synaptic mechanisms to account for synaptic deficits in Alzheimer's disease models, presynaptic mechanisms may also be affected. Here, using whole cell patch-clamp recording, coefficient of variation (CV) analysis suggested a profound presynaptic deficit in long-term potentiation (LTP) of CA3:CA1 synapses in hAPP-J20 mice. While the membrane-impermeable ionotropic NMDA receptor (NMDAR) blocker norketamine in the post-synaptic recording electrode had no effect on LTP, additional bath application of the ionotropic NMDAR blockers MK801 could replicate the deficit in LTP in wild type mice. In contrast to LTP, the paired-pulse ratio and short-term facilitation (STF) were aberrantly increased in hAPP-J20 mice. These synaptic deficits in hAPP-J20 mice were associated with reduced phosphorylation of NMDAR GluN2B and the synaptic vesicle recycling protein NSF (N-ethylmaleimide sensitive factor). Phosphorylation of both proteins, together with synaptic plasticity and cognitive function, were restored by PTP1B ablation or inhibition by the PTP1B-selective inhibitor Trodusquemine. Taken together, our results indicate that PTP1B impairs presynaptic NMDAR-mediated synaptic plasticity required for spatial learning in a mouse model of Alzheimer's disease. Since Trodusquemine has undergone phase 1/2 clinical trials to treat obesity, it could be repurposed to treat Alzheimer's disease.
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Affiliation(s)
- Li Zhang
- Neuroscience, Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada; University of Ottawa Brain and Mind Institute, Ottawa, ON K1H8M5, Canada
| | - Zhaohong Qin
- Neuroscience, Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada; University of Ottawa Brain and Mind Institute, Ottawa, ON K1H8M5, Canada
| | - Fariba Sharmin
- Neuroscience, Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada; University of Ottawa Brain and Mind Institute, Ottawa, ON K1H8M5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Wei Lin
- Neuroscience, Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada; University of Ottawa Brain and Mind Institute, Ottawa, ON K1H8M5, Canada
| | - Konrad M Ricke
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada; University of Ottawa Heart Institute, Ottawa, ON K1Y4W7, Canada
| | - Michael A Zasloff
- Georgetown University School of Medicine, MedStar Georgetown Transplant Institute, Washington, DC, 2007, USA
| | - Alexandre F R Stewart
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada; University of Ottawa Heart Institute, Ottawa, ON K1Y4W7, Canada.
| | - Hsiao-Huei Chen
- Neuroscience, Ottawa Hospital Research Institute, Ottawa, ON K1H8M5, Canada; University of Ottawa Brain and Mind Institute, Ottawa, ON K1H8M5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Department of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
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8
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Ruete MC, Zarelli VEP, Masone D, de Paola M, Bustos DM, Tomes CN. A connection between reversible tyrosine phosphorylation and SNARE complex disassembly activity of N-ethylmaleimide-sensitive factor unveiled by the phosphomimetic mutant N-ethylmaleimide-sensitive factor-Y83E. ACTA ACUST UNITED AC 2019; 25:344-358. [DOI: 10.1093/molehr/gaz031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/16/2019] [Accepted: 06/03/2019] [Indexed: 12/26/2022]
Abstract
Abstract
N-ethylmaleimide-sensitive factor (NSF) disassembles fusion-incompetent cis soluble-NSF attachment protein receptor (SNARE) complexes making monomeric SNAREs available for subsequent trans pairing and fusion. In most cells the activity of NSF is constitutive, but in Jurkat cells and sperm it is repressed by tyrosine phosphorylation; the phosphomimetic mutant NSF–Y83E inhibits secretion in the former. The questions addressed here are if and how the NSF mutant influences the configuration of the SNARE complex. Our model is human sperm, where the initiation of exocytosis (acrosome reaction (AR)) de-represses the activity of NSF through protein tyrosine phosphatase 1B (PTP1B)-mediated dephosphorylation. We developed a fluorescence microscopy-based method to show that capacitation increased, and challenging with an AR inducer decreased, the number of cells with tyrosine-phosphorylated PTP1B substrates in the acrosomal domain. Results from bioinformatic and biochemical approaches using purified recombinant proteins revealed that NSF–Y83E bound PTP1B and thereupon inhibited its catalytic activity. Mutant NSF introduced into streptolysin O-permeabilized sperm impaired cis SNARE complex disassembly, blocking the AR; subsequent addition of PTP1B rescued exocytosis. We propose that NSF–Y83E prevents endogenous PTP1B from dephosphorylating sperm NSF, thus maintaining NSF’s activity in a repressed mode and the SNARE complex unable to dissociate. The contribution of this paper to the sperm biology field is the detection of PTP1B substrates, one of them likely being NSF, whose tyrosine phosphorylation status varies during capacitation and the AR. The contribution of this paper to the membrane traffic field is to have generated direct evidence that explains the dominant-negative role of the phosphomimetic mutant NSF–Y83E.
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Affiliation(s)
- María Celeste Ruete
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Valeria Eugenia Paola Zarelli
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ingeniería, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Matilde de Paola
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- Instituto de Medicina y Biología Experimental de Cuyo–Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Diego Martín Bustos
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia Nora Tomes
- Instituto de Histología y Embriología de Mendoza Dr Mario H. Burgos–CONICET, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
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9
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Hagiuda J, Takasaki N, Oya M, Ishikawa H, Narimatsu H. Mutation of GALNTL5 gene identified in patients diagnosed with asthenozoospermia. HUM FERTIL 2019; 23:226-233. [PMID: 30628500 DOI: 10.1080/14647273.2018.1562239] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Asthenozoospermia is commonly observed in infertile men. However, very few causative gene mutations have been identified because an efficient detection method has not been established. We previously identified a patient with asthenozoospermia carrying a heterozygous point deletion in GALNTL5 by detecting an abnormal reduction in the abundance of GALNTL5 and other marker proteins. To identify other mutations in GALNTL5, we screened sperm samples from 208 infertile men mainly diagnosed with asthenozoospermia using the same method, and conducted next-generation sequencing. Consequently, another case of GALNTL5 mutation was detected only in sperm at a low frequency but not in the somatic blood cells of a patient diagnosed with asthenozoospermia. In this patient, sperm motility improved and the mutation disappeared at 2 years after the first observation. In this man, carrying a heterozygotic deficiency of GALNTL5, the swim-up method was useful to concentrate the spermatozoa without mutation. Intracytoplasmic sperm injection of the selected motile spermatozoa into oocytes of the patient's partner resulted in successful conception, and a female child was safely delivered. These results suggest the feasibility of our approach for the screening and treatment of asthenozoospermia associated with GALNTL5 mutation.
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Affiliation(s)
- Jun Hagiuda
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.,Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Ichikawa, Japan.,Department of Urology, School of Medicine, Keio University, Tokyo, Japan
| | - Nobuyoshi Takasaki
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.,Bell Research Center Obstetrics and Gynecology, Academic Research and Industrial-Academia Collaboration, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mototsugu Oya
- Department of Urology, School of Medicine, Keio University, Tokyo, Japan
| | - Hiromichi Ishikawa
- Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Ichikawa, Japan
| | - Hisashi Narimatsu
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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10
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Liu C, Liu Y, Larsen K, Hou YP, Callesen H. Calcium-sensing receptor (CASR) is involved in porcine in vitro fertilisation and early embryo development. Reprod Fertil Dev 2018; 30:391-398. [PMID: 28712411 DOI: 10.1071/rd16338] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 06/25/2017] [Indexed: 11/23/2022] Open
Abstract
It has been demonstrated that extracellular calcium is necessary in fertilisation and embryo development but the mechanism is still not well understood. The present study mainly focussed on the extracellular calcium effector called the calcium-sensing receptor (CASR) and examined its expression in porcine gametes and embryos and its function during fertilisation and early embryo development. By using reverse transcription polymerase chain reaction, CASR was found to be expressed in porcine oocytes, spermatozoa and embryos at different developmental stages. Functionally, medium supplementation with a CASR agonist or an antagonist during in vitro fertilisation (IVF) and in vitro culture (IVC) was tested. During fertilisation, the presence of a CASR agonist increased sperm penetration rate and decreased polyspermy rate leading to an increased normal fertilisation rate. During embryo development, for the IVF embryos, agonist treatment during IVC significantly increased cleavage rate and blastocyst formation rate compared with the control group. Furthermore, parthenogenetically activated embryos showed similar results with lower cleavage and blastocyst formation rates in the antagonist group than in the other groups. It was concluded that CASR, as the effector of extracellular calcium, modulates porcine fertilisation and early embryo development.
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Affiliation(s)
- C Liu
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, No. 2, Yuanmingyuan West Road, Haidian District, Beijing 100193, China
| | - Y Liu
- Department of Animal Science, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark
| | - K Larsen
- Department of Molecular Biology and Genetics, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark
| | - Y P Hou
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, No. 2, Yuanmingyuan West Road, Haidian District, Beijing 100193, China
| | - H Callesen
- Department of Animal Science, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark
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11
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Impaired sperm maturation in conditional Lcn6 knockout mice†. Biol Reprod 2017; 98:28-41. [DOI: 10.1093/biolre/iox128] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 10/12/2017] [Indexed: 12/23/2022] Open
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12
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Bondarenko O, Dzyuba B, Rodina M, Cosson J. Role of Ca2+ in the IVM of spermatozoa from the sterlet Acipenser ruthenus. Reprod Fertil Dev 2017; 29:1319-1328. [DOI: 10.1071/rd16145] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 04/20/2016] [Indexed: 12/13/2022] Open
Abstract
The role of Ca2+ in sturgeon sperm maturation and motility was investigated. Sperm from mature male sterlets (Acipenser ruthenus) were collected from the Wolffian duct and testis 24 h after hormone induction. Testicular spermatozoa (TS) were incubated in Wolffian duct seminal fluid (WDSF) for 5 min at 20°C and were designated ‘TS after IVM’ (TSM). Sperm motility was activated in media with different ion compositions, with motility parameters analysed from standard video microscopy records. To investigate the role of calcium transport in the IVM process, IVM was performed (5 min at 20°C) in the presence of 2 mM EGTA, 100 µM Verapamil or 100 µM Tetracaine. No motility was observed in the case of TS (10 mM Tris, 25 mM NaCl, 50 mM Sucr with or without the addition of 2 mM EGTA). Both incubation of TS in WDSF and supplementation of the activation medium with Ca2+ led to sperm motility. The minimal Ca2+ concentration required for motility activation of Wolffian duct spermatozoa, TS and TSM was determined (1–2 nM for Wolffian duct spermatozoa and TSM; approximately 0.6 mM for TS). Motility was obtained after the addition of verapamil to the incubation medium during IVM, whereas the addition of EGTA completely suppressed motility, implying Ca2+ involvement in sturgeon sperm maturation. Further studies into the roles of Ca2+ transport in sturgeon sperm maturation and motility are required.
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Agarwal A, Sharma R, Samanta L, Durairajanayagam D, Sabanegh E. Proteomic signatures of infertile men with clinical varicocele and their validation studies reveal mitochondrial dysfunction leading to infertility. Asian J Androl 2016; 18:282-91. [PMID: 26732106 PMCID: PMC4770500 DOI: 10.4103/1008-682x.170445] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
To study the major differences in the distribution of spermatozoa proteins in infertile men with varicocele by comparative proteomics and validation of their level of expression. The study-specific estimates for each varicocele outcome were combined to identify the proteins involved in varicocele-associated infertility in men irrespective of stage and laterality of their clinical varicocele. Expression levels of 5 key proteins (PKAR1A, AK7, CCT6B, HSPA2, and ODF2) involved in stress response and sperm function including molecular chaperones were validated by Western blotting. Ninety-nine proteins were differentially expressed in the varicocele group. Over 87% of the DEP involved in major energy metabolism and key sperm functions were underexpressed in the varicocele group. Key protein functions affected in the varicocele group were spermatogenesis, sperm motility, and mitochondrial dysfunction, which were further validated by Western blotting, corroborating the proteomics analysis. Varicocele is essentially a state of energy deprivation, hypoxia, and hyperthermia due to impaired blood supply, which is corroborated by down-regulation of lipid metabolism, mitochondrial electron transport chain, and Krebs cycle enzymes. To corroborate the proteomic analysis, expression of the 5 identified proteins of interest was validated by Western blotting. This study contributes toward establishing a biomarker “fingerprint” to assess sperm quality on the basis of molecular parameters.
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Affiliation(s)
- Ashok Agarwal
- American Center for Reproductive Medicine, Cleveland Clinic, Cleveland, OH, USA
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Li Y, Lin S, Luo M, Guo H, Chen J, Ma Q, Gu Y, Jiang Z, Gui Y. FAM170B, a novel acrosomal protein involved in fertilization in mice. Mol Reprod Dev 2015; 82:787-96. [PMID: 26179146 DOI: 10.1002/mrd.22523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 07/06/2015] [Indexed: 02/05/2023]
Abstract
The acrosome is a specialized organelle that covers the anterior region of the sperm nucleus, and plays an essential role in mammalian fertilization. Although acrosome biogenesis is an important aspect of spermiogenesis, the molecular mechanism that regulates this event remains unknown. In the present study, we identified a novel gene, Fam170b (family with sequence similarity 170, member B), exclusively expressed in mouse testes. Fam170b expression first started at postnatal week 3, and increased in an age-dependent manner until plateauing in adulthood. Immunofluorescence staining revealed its enrichment in round spermatids, and redistribution to a perinuclear spot adjacent to the Golgi and the acrosome of elongating spermatids and spermatozoa; this localization was shared between mouse and human spermatozoa. Anti-FAM170B antibody was remarkably found to inhibit murine in vitro fertilization, specifically blocking the acrosome reaction. We further determined that FAM170B interacts with GOPC (Golgi-associated PDZ and coiled-coil motif containing protein) during acrosome formation, as verified by immunofluorescence and co-immunoprecipitation assays. Thus, we document the expression and function for the endogenous acrosomal protein FAM170B during spermiogenesis and fertilization.
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Affiliation(s)
- Yuchi Li
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
- Shantou University Medical College, Shantou, P.R. China
| | - Shouren Lin
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
| | - Manling Luo
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
- Shantou University Medical College, Shantou, P.R. China
| | - Huan Guo
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
- Guangzhou Medical University, Guangzhou, P.R. China
| | - Jianbo Chen
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
- Anhui Medical University, Hefei, P.R. China
| | - Qian Ma
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
| | - Yanli Gu
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
| | - Zhimao Jiang
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
| | - Yaoting Gui
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen, P.R. China
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15
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de Paola M, Bello OD, Michaut MA. Cortical Granule Exocytosis Is Mediated by Alpha-SNAP and N-Ethilmaleimide Sensitive Factor in Mouse Oocytes. PLoS One 2015; 10:e0135679. [PMID: 26267363 PMCID: PMC4534440 DOI: 10.1371/journal.pone.0135679] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/25/2015] [Indexed: 11/18/2022] Open
Abstract
Cortical granule exocytosis (CGE), also known as cortical reaction, is a calcium- regulated secretion that represents a membrane fusion process during meiotic cell division of oocytes. The molecular mechanism of membrane fusion during CGE is still poorly understood and is thought to be mediated by the SNARE pathway; nevertheless, it is unkown if SNAP (acronym for soluble NSF attachment protein) and NSF (acronym for N-ethilmaleimide sensitive factor), two key proteins in the SNARE pathway, mediate CGE in any oocyte model. In this paper, we documented the gene expression of α-SNAP, γ-SNAP and NSF in mouse oocytes. Western blot analysis showed that the expression of these proteins maintains a similar level during oocyte maturation and early activation. Their localization was mainly observed at the cortical region of metaphase II oocytes, which is enriched in cortical granules. To evaluate the function of these proteins in CGE we set up a functional assay based on the quantification of cortical granules metaphase II oocytes activated parthenogenetically with strontium. Endogenous α-SNAP and NSF proteins were perturbed by microinjection of recombinant proteins or antibodies prior to CGE activation. The microinjection of wild type α-SNAP and the negative mutant of α-SNAP L294A in metaphase II oocytes inhibited CGE stimulated by strontium. NEM, an irreversibly inhibitor of NSF, and the microinjection of the negative mutant NSF D1EQ inhibited cortical reaction. The microinjection of anti-α-SNAP and anti-NSF antibodies was able to abolish CGE in activated metaphase II oocytes. The microinjection of anti-γ SNAP antibody had no effect on CGE. Our findings indicate, for the first time in any oocyte model, that α-SNAP, γ-SNAP, and NSF are expressed in mouse oocytes. We demonstrate that α-SNAP and NSF have an active role in CGE and propose a working model.
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Affiliation(s)
- Matilde de Paola
- Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Oscar Daniel Bello
- Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Marcela Alejandra Michaut
- Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
- * E-mail:
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16
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Abstract
Exocytosis is a highly regulated process that consists of multiple functionally, kinetically and/or morphologically definable stages such as recruitment, targeting, tethering and docking of secretory vesicles with the plasma membrane, priming of the fusion machinery and calcium-triggered membrane fusion. After fusion, the membrane around the secretory vesicle is incorporated into the plasma membrane and the granule releases its contents. The proteins involved in these processes belong to several highly conserved families: Rab GTPases, SNAREs (soluble NSF-attachment protein receptors), α-SNAP (α-NSF attachment protein), NSF (N-ethylmaleimide-sensitive factor), Munc13 and -18, complexins and synaptotagmins. In the present article, the molecules of exocytosis are reviewed, using human sperm as a model system. Sperm exocytosis is driven by isoforms of the same proteinaceous fusion machinery mentioned above, with their functions orchestrated in a hierarchically organized and unidirectional signalling cascade. In addition to the universal exocytosis regulator calcium, this cascade includes other second messengers such as diacylglycerol, inositol 1,4,5-trisphosphate and cAMP, as well as the enzymes that synthesize them and their target proteins. Of special interest is the cAMP-binding protein Epac (exchange protein directly activated by cAMP) due in part to its enzymatic activity towards Rap. The activation of Epac and Rap leads to a highly localized calcium signal which, together with assembly of the SNARE complex, governs the final stages of exocytosis. The source of this releasable calcium is the secretory granule itself.
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17
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Bustos MA, Roggero CM, De la Iglesia PX, Mayorga LS, Tomes CN. GTP-bound Rab3A exhibits consecutive positive and negative roles during human sperm dense-core granule exocytosis. J Mol Cell Biol 2015; 6:286-98. [PMID: 25053757 DOI: 10.1093/jmcb/mju021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Exocytosis of mammalian sperm dense-core secretory granule relies on the same fusion molecules as all other secretory cells; one such molecule is the small GTPase Rab3A. Here, we report an in-depth biochemical characterization of the role of Rab3A in secretion by scrutinizing the exocytotic response of streptolysin O-permeabilized human sperm to the acute application of a number of Rab3A-containing constructs and correlating the findings with those gathered with the endogenous protein. Full length, geranylgeranylated, and active Rab3A elicited human sperm exocytosis per se. With Rab3A/Rab22A chimeric proteins, we demonstrated that the carboxy-terminal domain of the Rab3A molecule was necessary and sufficient to promote exocytosis, whereas its amino-terminus prevented calcium-triggered secretion. Interestingly, full length Rab3A halted secretion when added after the docking of the acrosome to the plasma membrane. This effect depended on the inability of Rab3A to hydrolyze GTP. We combined modified immunofluorescence and acrosomal staining protocols to detect membrane fusion and the activation status of endogenous Rab3 simultaneously in individual cells, and found that GTP hydrolysis on endogenous Rab3 was mandatory for fusion pores to open. Our findings contribute to establishing that Rab3 modulates regulated exocytosis differently depending on the nucleotide bound and the exocytosis stage under study.
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Affiliation(s)
- Matías A Bustos
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Carlos M Roggero
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina Present address: Department of Biophysics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Paola X De la Iglesia
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina Present address: Servicio de Patología, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
| | - Luis S Mayorga
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia N Tomes
- Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
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18
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Sosa CM, Pavarotti MA, Zanetti MN, Zoppino FCM, De Blas GA, Mayorga LS. Kinetics of human sperm acrosomal exocytosis. Mol Hum Reprod 2014; 21:244-54. [PMID: 25452326 DOI: 10.1093/molehr/gau110] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The acrosome reaction is a unique event in the lifespan of sperm characterized by the exocytosis of the acrosomal content and the release of hybrid vesicles formed by patches of the outer acrosomal membrane and the plasma membrane. This unique regulated exocytosis is mediated by essentially the same membrane fusion machinery present in neuroendocrine cells. However, whereas secretion in neuroendocrine cells occurs in less than a second, the acrosome reaction is normally assessed after several minutes of incubation with inducers. In this report, we measured the kinetics of human sperm exocytosis triggered by two stimuli (calcium ionophore and progesterone) by using electron microscopy and three different approaches based on the incorporation of fluorescent Pisum sativum agglutinin into the acrosome upon opening of fusion pores connecting the extracellular medium with the acrosomal lumen. The results with the different methods are consistent with a slow kinetics (t½ = 14 min). We also manipulated the system to measure different steps of the process. We observed that cytosolic calcium increased with a relatively fast kinetics (t½ = 0.1 min). In contrast, the swelling of the acrosomal granule that precedes exocytosis was a slow process (t½ = 13 min). When swelling was completed, the fusion pore opening was fast (t½ = 0.2 min). The results indicate that acrosomal swelling is the slowest step and it determines the kinetics of the acrosome reaction. After the swelling is completed, the efflux of calcium from intracellular stores triggers fusion pores opening and the release of hybrid vesicles in seconds.
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Affiliation(s)
- C M Sosa
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
| | - M A Pavarotti
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
| | - M N Zanetti
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina Present address: Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - F C M Zoppino
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina Present address: Laboratory of Oncology, Institute of Experimental Medicine and Biology of Cuyo (IMBECU - CONICET), 5500 Mendoza, Argentina
| | - G A De Blas
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
| | - L S Mayorga
- IHEM (CONICET-UNCuyo), School of Medicine, National University of Cuyo, 5500 Mendoza, Argentina
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19
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Calcium influx and male fertility in the context of the sperm proteome: an update. BIOMED RESEARCH INTERNATIONAL 2014; 2014:841615. [PMID: 24877140 PMCID: PMC4022195 DOI: 10.1155/2014/841615] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 01/14/2014] [Indexed: 01/06/2023]
Abstract
Freshly ejaculated spermatozoa are incapable or poorly capable of fertilizing an oocyte. The fertilization aptness of spermatozoa depends on the appropriate and time-dependent acquisition of hyperactivation, chemotaxis, capacitation, and the acrosome reaction, where calcium (Ca2+) is extensively involved in almost every step. A literature review showed that several ion channel proteins are likely responsible for regulation of the Ca2+ uptake in spermatozoa. Therefore, manipulation of the functions of channel proteins is closely related to Ca2+ influx, ultimately affecting male fertility. Recently, it has been shown that, together with different physiological stimuli, protein-protein interaction also modifies the Ca2+ influx mechanism in spermatozoa. Modern proteomic analyses have identified several sperm proteins, and, therefore, these findings might provide further insight into understanding the Ca2+ influx, protein functions, and regulation of fertility. The objective of this review was to synthesize the published findings on the Ca2+ influx mechanism in mammalian spermatozoa and its implications for the regulation of male fertility in the context of sperm proteins. Finally, Pathway Studio (9.0) was used to catalog the sperm proteins that regulate the Ca2+ influx signaling by using the information available from the PubMed database following a MedScan Reader (5.0) search.
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20
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Shi L, Zhang Q, Xu B, Jiang X, Dai Y, Zhang CY, Zen K. Sustained high protein-tyrosine phosphatase 1B activity in the sperm of obese males impairs the sperm acrosome reaction. J Biol Chem 2014; 289:8432-41. [PMID: 24519936 DOI: 10.1074/jbc.m113.517466] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Evidence of a causal link between male obesity and subfertility or infertility has been demonstrated previously. However, the mechanism underlying this link is incompletely understood. Here, we report that sustained high protein-tyrosine phosphatase 1B (PTP1B) activity in sperm of obese donors plays an essential role in coupling male obesity and subfertility or infertility. First, PTP1B level and activity were significantly higher in sperm from ob/ob mice than in wild-type littermates. High PTP1B level and activity in sperm was also observed in obese patients compared with non-obese donors. The enhanced sperm PTP1B level and activity in ob/ob mice and obese patients correlated with a defect of the sperm acrosome reaction (AR). Second, treating sperm from male ob/ob mice or obese men with a specific PTP1B inhibitor largely restored the sperm AR. Finally, blockade of sperm AR by enhanced PTP1B activity in male ob/ob mice or obese men was due to prolonged dephosphorylation of N-ethylmaleimide-sensitive factor by PTP1B, leading to the inability to reassemble the trans-SNARE complexes, which is a critical step in sperm acrosomal exocytosis. In summary, our study demonstrates for the first time that a sustained high PTP1B level or activity in the sperm of obese donors causes a defect of sperm AR and that PTP1B is a novel potential therapeutic target for male infertility treatment.
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Affiliation(s)
- Lei Shi
- From the Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China and
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21
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Equatorin is not essential for acrosome biogenesis but is required for the acrosome reaction. Biochem Biophys Res Commun 2014; 444:537-42. [DOI: 10.1016/j.bbrc.2014.01.080] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 01/20/2014] [Indexed: 11/21/2022]
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22
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Takasaki N, Tachibana K, Ogasawara S, Matsuzaki H, Hagiuda J, Ishikawa H, Mochida K, Inoue K, Ogonuki N, Ogura A, Noce T, Ito C, Toshimori K, Narimatsu H. A heterozygous mutation of GALNTL5 affects male infertility with impairment of sperm motility. Proc Natl Acad Sci U S A 2014; 111:1120-5. [PMID: 24398516 PMCID: PMC3903224 DOI: 10.1073/pnas.1310777111] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
For normal fertilization in mammals, it is important that functionally mature sperm are motile and have a fully formed acrosome. The glycosyltransferase-like gene, human polypeptide N-acetylgalactosaminyltransferase-like protein 5 (GALNTL5), belongs to the polypeptide N-acetylgalactosamine-transferase (pp-GalNAc-T) gene family because of its conserved glycosyltransferase domains, but it uniquely truncates the C-terminal domain and is expressed exclusively in human testis. However, glycosyltransferase activity of the human GALNTL5 protein has not been identified by in vitro assay thus far. Using mouse Galntl5 ortholog, we have examined whether GALNTL5 is a functional molecule in spermatogenesis. It was observed that mouse GALNTL5 localizes in the cytoplasm of round spermatids in the region around the acrosome of elongating spermatids, and finally in the neck region of spermatozoa. We attempted to establish Galntl5-deficient mutant mice to investigate the role of Galntl5 in spermiogenesis and found that the heterozygous mutation affected male fertility due to immotile sperm, which is diagnosed as asthenozoospermia, an infertility syndrome in humans. Furthermore, the heterozygous mutation of Galntl5 attenuated glycolytic enzymes required for motility, disrupted protein loading into acrosomes, and caused aberrant localization of the ubiquitin-proteasome system. By comparing the protein compositions of sperm from infertile males, we found a deletion mutation of the exon of human GALNTL5 gene in a patient with asthenozoospermia. This strongly suggests that the genetic mutation of human GALNTL5 results in male infertility with the reduction of sperm motility and that GALNTL5 is a functional molecule essential for mammalian sperm formation.
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Affiliation(s)
- Nobuyoshi Takasaki
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
| | - Kouichi Tachibana
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
| | - Satoshi Ogasawara
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
| | - Hideki Matsuzaki
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
| | - Jun Hagiuda
- Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Ichikawa, Chiba 272-8513, Japan
| | - Hiromichi Ishikawa
- Department of Urology, Ichikawa General Hospital, Tokyo Dental College, Ichikawa, Chiba 272-8513, Japan
| | - Keiji Mochida
- RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
| | - Kimiko Inoue
- RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
| | - Narumi Ogonuki
- RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
| | - Atsuo Ogura
- RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074, Japan
| | - Toshiaki Noce
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan; and
| | - Chizuru Ito
- Department of Anatomy and Developmental Biology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba 260-8670, Japan
| | - Kiyotaka Toshimori
- Department of Anatomy and Developmental Biology, Graduate School of Medicine, Chiba University, Chuo-ku, Chiba 260-8670, Japan
| | - Hisashi Narimatsu
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
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MARCKS protein is phosphorylated and regulates calcium mobilization during human acrosomal exocytosis. PLoS One 2013; 8:e64551. [PMID: 23704996 PMCID: PMC3660367 DOI: 10.1371/journal.pone.0064551] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 04/17/2013] [Indexed: 12/01/2022] Open
Abstract
Acrosomal exocytosis is a calcium-regulated exocytosis that can be triggered by PKC activators. The involvement of PKC in acrosomal exocytosis has not been fully elucidated, and it is unknown if MARCKS, the major substrate for PKC, participates in this exocytosis. Here, we report that MARCKS is expressed in human spermatozoa and localizes to the sperm head and the tail. Calcium- and phorbol ester-triggered acrosomal exocytosis in permeabilized sperm was abrogated by different anti-MARCKS antibodies raised against two different domains, indicating that the protein participates in acrosomal exocytosis. Interestingly, an anti-phosphorylated MARCKS antibody was not able to inhibit secretion. Similar results were obtained using recombinant proteins and phospho-mutants of MARCKS effector domain (ED), indicating that phosphorylation regulates MARCKS function in acrosomal exocytosis. It is known that unphosphorylated MARCKS sequesters PIP2. This phospholipid is the precursor for IP3, which in turn triggers release of calcium from the acrosome during acrosomal exocytosis. We found that PIP2 and adenophostin, a potent IP3-receptor agonist, rescued MARCKS inhibition in permeabilized sperm, suggesting that MARCKS inhibits acrosomal exocytosis by sequestering PIP2 and, indirectly, MARCKS regulates the intracellular calcium mobilization. In non-permeabilized sperm, a permeable peptide of MARCKS ED also inhibited acrosomal exocytosis when stimulated by a natural agonist such as progesterone, and pharmacological inducers such as calcium ionophore and phorbol ester. The preincubation of human sperm with the permeable MARCKS ED abolished the increase in calcium levels caused by progesterone, demonstrating that MARCKS regulates calcium mobilization. In addition, the phosphorylation of MARCKS increased during acrosomal exocytosis stimulated by the same activators. Altogether, these results show that MARCKS is a negative modulator of the acrosomal exocytosis, probably by sequestering PIP2, and that it is phosphorylated during acrosomal exocytosis.
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Gupta SK, Bhandari B, Shrestha A, Biswal BK, Palaniappan C, Malhotra SS, Gupta N. Mammalian zona pellucida glycoproteins: structure and function during fertilization. Cell Tissue Res 2013; 349:665-78. [PMID: 22298023 DOI: 10.1007/s00441-011-1319-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 12/21/2011] [Indexed: 12/15/2022]
Abstract
Zona pellucida (ZP) is a glycoproteinaceous translucent matrix that surrounds the mammalian oocyte and plays a critical role in the accomplishment of fertilization. In humans, it is composed of 4 glycoproteins designated as ZP1, ZP2, ZP3 and ZP4, whereas mouse ZP is composed of ZP1, ZP2 and ZP3 (Zp4 being a pseudogene). In addition to a variable sequence identity of a given zona protein among various species, human ZP1 and ZP4 are paralogs and mature polypeptide chains share an identity of 47%. Employing either affinity purified native or recombinant human zona proteins, it has been demonstrated that ZP1, ZP3 and ZP4 bind to the capacitated human spermatozoa and induce an acrosome reaction, whereas in mice, ZP3 acts as the putative primary sperm receptor. Human ZP2 only binds to acrosome-reacted spermatozoa and thus may be acting as a secondary sperm receptor. In contrast to O-linked glycans of ZP3 in mice, N-linked glycans of human ZP3 and ZP4 are more relevant for induction of the acrosome reaction. Recent studies suggest that Sialyl-Lewis(x) sequence present on both N- and O-glycans of human ZP play an important role in human sperm-egg binding. There are subtle differences in the downstream signaling events associated with ZP3 versus ZP1/ZP4-mediated induction of the acrosome reaction. For example, ZP3 but not ZP1/ZP4-mediated induction of the acrosome reaction is dependent on the activation of the Gi protein-coupled receptor. Thus, various studies suggest that, in contrast to mice, in humans more than one zona protein binds to spermatozoa and induces an acrosome reaction.
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Affiliation(s)
- Satish K Gupta
- Reproductive Cell Biology Laboratory, National Institute of Immunology, New Delhi, India.
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Perfringolysin O as a useful tool to study human sperm physiology. Fertil Steril 2013; 99:99-106.e2. [DOI: 10.1016/j.fertnstert.2012.08.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/09/2012] [Accepted: 08/22/2012] [Indexed: 11/27/2022]
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Rodríguez F, Zanetti MN, Mayorga LS, Tomes CN. Munc18-1 controls SNARE protein complex assembly during human sperm acrosomal exocytosis. J Biol Chem 2012; 287:43825-39. [PMID: 23091057 DOI: 10.1074/jbc.m112.409649] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The spermatozoon is a very specialized cell capable of carrying out a limited set of functions with high efficiency. Sperm are then excellent model cells to dissect fundamental processes such as regulated exocytosis. The secretion of the single dense-core granule of mammalian spermatozoa relies on the same highly conserved molecules and goes through the same stages as exocytosis in other types of cells. In this study, we describe the presence of Munc18-1 in human sperm and show that this protein has an essential role in acrosomal exocytosis. We observed that inactivation of endogenous Munc18-1 with a specific antibody precluded the stabilization of trans-SNARE complexes and inhibited acrosomal exocytosis. Addition of recombinant Munc18-1 blocked secretion by sequestering monomeric syntaxin, an effect that was rescued by α-soluble NSF attachment protein. By electron microscopy, we observed that both the anti-Munc18-1 antibody and recombinant Munc18-1 inhibited the docking of the acrosome to the plasma membrane. In conclusion, our results indicate that Munc18-1 plays a key role in the dynamics of trans-SNARE complex assembly and/or stabilization, a process that is necessary for the docking of the outer acrosomal membrane to the plasma membrane and subsequent fusion pore opening.
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Affiliation(s)
- Facundo Rodríguez
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina
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Rab27 and Rab3 sequentially regulate human sperm dense-core granule exocytosis. Proc Natl Acad Sci U S A 2012; 109:E2057-66. [PMID: 22753498 DOI: 10.1073/pnas.1121173109] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Two so-called "secretory Rabs," Rab3 and Rab27, regulate late steps during dense-core vesicle exocytosis in neuroendocrine cells. Sperm contain a single large dense-core granule that is released by regulated exocytosis (termed the acrosome reaction) during fertilization or on exposure to inducers in vitro. Sperm exocytosis uses the same fusion machinery as neurons and neuroendocrine cells, with an additional requirement for active Rab3. Here we show that Rab27 is also required for the acrosome reaction, as demonstrated by the inability of inducers to elicit exocytosis when streptolysin O-permeabilized human sperm were loaded with inhibitory anti-Rab27 antibodies or the Rab27-GTP binding domain of the effector Slac2-b. The levels of GTP-bound Rab27 increased on initiation of exocytosis, as did the proportion of GTP-bound Rab3A. We have developed a fluorescence microscopy-based method for detecting endogenous Rab3A-GTP and Rab27-GTP in the acrosomal region of human sperm. Challenge with an inducer increased the population of cells exhibiting GTP-bound Rabs in this subcellular domain. Interestingly, introducing recombinant Rab27A loaded with GTP-γ-S into sperm elicited a remarkable increase in the number of cells evincing GTP-bound Rab3A. In the converse condition, recombinant Rab3A did not modify the percentage of Rab27-GTP-containing cells. Furthermore, Rab27A-GTP recruited a Rab3 GDP/GTP exchange factor (GEF) activity. Our findings suggest that Rab27/Rab3A constitutes a Rab-GEF cascade in dense-core vesicle exocytosis.
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Lopez CI, Pelletán LE, Suhaiman L, De Blas GA, Vitale N, Mayorga LS, Belmonte SA. Diacylglycerol stimulates acrosomal exocytosis by feeding into a PKC- and PLD1-dependent positive loop that continuously supplies phosphatidylinositol 4,5-bisphosphate. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1186-99. [PMID: 22609963 DOI: 10.1016/j.bbalip.2012.05.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 04/04/2012] [Accepted: 05/07/2012] [Indexed: 01/08/2023]
Abstract
Acrosomal exocytosis involves a massive fusion between the outer acrosomal and the plasma membranes of the spermatozoon triggered by stimuli that open calcium channels at the plasma membrane. Diacylglycerol has been implicated in the activation of these calcium channels. Here we report that this lipid promotes the efflux of intraacrosomal calcium and triggers exocytosis in permeabilized human sperm, implying that diacylglycerol activates events downstream of the opening of plasma membrane channels. Furthermore, we show that calcium and diacylglycerol converge in a signaling pathway leading to the production of phosphatidylinositol 4,5-bisphosphate (PIP(2)). Addition of diacylglycerol promotes the PKC-dependent activation of PLD1. Rescue experiments adding phosphatidic acid or PIP(2) and direct measurement of lipid production suggest that both PKC and PLD1 promote PIP(2) synthesis. Inhibition of different steps of the pathway was reverted by adenophostin, an agonist of IP(3)-sensitive calcium channels, indicating that PIP(2) is necessary to keep these channels opened. However, phosphatidic acid, PIP(2), or adenophostin could not trigger exocytosis by themselves, indicating that diacylglycerol must also activate another factor. We found that diacylglycerol and phorbol ester stimulate the accumulation of the GTP-bound form of Rab3A. Together our results indicate that diacylglycerol promotes acrosomal exocytosis by i) maintaining high levels of IP(3) - an effect that depends on a positive feedback loop leading to the production of PIP(2) - and ii) stimulating the activation of Rab3A, which in turn initiates a cascade of protein interactions leading to the assembly of SNARE complexes and membrane fusion.
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Affiliation(s)
- Cecilia I Lopez
- Instituto de Histología y Embriología, Universidad Nacional de Cuyo, Mendoza, Argentina
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29
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Rodríguez F, Bustos MA, Zanetti MN, Ruete MC, Mayorga LS, Tomes CN. α-SNAP prevents docking of the acrosome during sperm exocytosis because it sequesters monomeric syntaxin. PLoS One 2011; 6:e21925. [PMID: 21789195 PMCID: PMC3138754 DOI: 10.1371/journal.pone.0021925] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 06/09/2011] [Indexed: 11/30/2022] Open
Abstract
α-SNAP has an essential role in membrane fusion that consists of bridging cis SNARE complexes to NSF. α-SNAP stimulates NSF, which releases itself, α-SNAP, and individual SNAREs that subsequently re-engage in the trans arrays indispensable for fusion. α-SNAP also binds monomeric syntaxin and NSF disengages the α-SNAP/syntaxin dimer. Here, we examine why recombinant α-SNAP blocks secretion in permeabilized human sperm despite the fact that the endogenous protein is essential for membrane fusion. The only mammalian organism with a genetically modified α-SNAP is the hyh mouse strain, which bears a M105I point mutation; males are subfertile due to defective sperm exocytosis. We report here that recombinant α-SNAP-M105I has greater affinity for the cytosolic portion of immunoprecipitated syntaxin than the wild type protein and in consequence NSF is less efficient in releasing the mutant. α-SNAP-M105I is a more potent sperm exocytosis blocker than the wild type and requires higher concentrations of NSF to rescue its effect. Unlike other fusion scenarios where SNAREs are subjected to an assembly/disassembly cycle, the fusion machinery in sperm is tuned so that SNAREs progress uni-directionally from a cis configuration in resting cells to monomeric and subsequently trans arrays in cells challenged with exocytosis inducers. By means of functional and indirect immunofluorescense assays, we show that recombinant α-SNAPs — wild type and M105I — inhibit exocytosis because they bind monomeric syntaxin and prevent this SNARE from assembling with its cognates in trans. Sequestration of free syntaxin impedes docking of the acrosome to the plasma membrane assessed by transmission electron microscopy. The N-terminal deletion mutant α-SNAP-(160–295), unable to bind syntaxin, affects neither docking nor secretion. The implications of this study are twofold: our findings explain the fertility defect of hyh mice and indicate that assembly of SNAREs in trans complexes is essential for docking.
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Affiliation(s)
- Facundo Rodríguez
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Matías A. Bustos
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María N. Zanetti
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María C. Ruete
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Luis S. Mayorga
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudia N. Tomes
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
- * E-mail:
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Tardif S, Cormier N. Role of zonadhesin during sperm-egg interaction: a species-specific acrosomal molecule with multiple functions. Mol Hum Reprod 2011; 17:661-8. [PMID: 21602212 DOI: 10.1093/molehr/gar039] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Sperm-zona adhesion is an essential event in mammalian fertilization, failure of which causes sterility. However, the molecular mechanisms involved in this process are still poorly understood. It has been suggested by few laboratories studying gamete interaction that acrosomal molecules are implicated in sperm-zona pellucida adhesion prior to the acrosome reaction (AR). Zonadhesin, a sperm-specific protein located in the acrosome is critically involved in zona binding. Here we describe the cellular and molecular interaction of zonadhesin during fertilization and also discuss its role in species-specific gamete interaction--an intriguing question in biology. We propose a model in which sperm could transiently expose acrosomal molecules that adhere to the zona independently of the AR in a 'kiss and run' mechanism. This could be a valuable framework for further investigations and a detailed understanding of the molecular events during gamete adhesion is likely to provide new approaches for the design of more effective male contraceptives and better diagnostic methods for sperm dysfunction.
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Affiliation(s)
- Steve Tardif
- Reproductive and Developmental Biology Group, Maternal and Child Health Sciences Laboratories, Centre for Oncology and Molecular Medicine, Division of Medical Sciences, Ninewells Hospital, University of Dundee, DD1 9SY, Dundee, UK.
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31
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Abstract
During mammalian fertilisation, the zona pellucida (ZP) matrix surrounding the oocyte is responsible for the binding of the spermatozoa to the oocyte and induction of the acrosome reaction (AR) in the ZP-bound spermatozoon. The AR is crucial for the penetration of the ZP matrix by spermatozoa. The ZP matrix in mice is composed of three glycoproteins designated ZP1, ZP2 and ZP3, whereas in humans, it is composed of four (ZP1, ZP2, ZP3 and ZP4). ZP3 acts as the putative primary sperm receptor and is responsible for AR induction in mice, whereas in humans (in addition to ZP3), ZP1 and ZP4 also induce the AR. The ability of ZP3 to induce the AR resides in its C-terminal fragment. O-linked glycans are critical for the murine ZP3-mediated AR. However, N-linked glycans of human ZP1, ZP3 and ZP4 have important roles in the induction of the AR. Studies with pharmacological inhibitors showed that the ZP3-induced AR involves the activation of the G(i)-coupled receptor pathway, whereas ZP1- and ZP4-mediated ARs are independent of this pathway. The ZP3-induced AR involves the activation of T-type voltage-operated calcium channels (VOCCs), whereas ZP1- and ZP4-induced ARs involve both T- and L-type VOCCs. To conclude, in mice, ZP3 is primarily responsible for the binding of capacitated spermatozoa to the ZP matrix and induction of the AR, whereas in humans (in addition to ZP3), ZP1 and ZP4 also participate in these stages of fertilisation.
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Tsai PS, Garcia-Gil N, van Haeften T, Gadella BM. How pig sperm prepares to fertilize: stable acrosome docking to the plasma membrane. PLoS One 2010; 5:e11204. [PMID: 20585455 PMCID: PMC2887851 DOI: 10.1371/journal.pone.0011204] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 05/26/2010] [Indexed: 11/19/2022] Open
Abstract
Background Mammalian sperms are activated in the oviduct. This process, which involves extensive sperm surface remodelling, is required for fertilization and can be mimicked under in vitro fertilization conditions (IVF). Methodology/Principal Findings Here we demonstrate that such treatments caused stable docking and priming of the acrosome membrane to the apical sperm head surface without the emergence of exocytotic membrane fusion. The interacting membranes could be isolated as bilamellar membrane structures after cell disruption. These membrane structures as well as whole capacitated sperm contained stable ternary trans-SNARE complexes that were composed of VAMP 3 and syntaxin 1B from the plasma membrane and SNAP 23 from the acrosomal membrane. This trans-SNARE complex was not observed in control sperm. Conclusions/Significance We propose that this capacitation driven membrane docking and stability thereof is a preparative step prior to the multipoint membrane fusions characteristic for the acrosome reaction induced by sperm-zona binding. Thus, sperm can be considered a valuable model for studying exocytosis.
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Affiliation(s)
- Pei-Shiue Tsai
- Department of Biochemistry and Cell Biology, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- Department of Farm Animal Health, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Núria Garcia-Gil
- Department of Biochemistry and Cell Biology, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Theo van Haeften
- Department of Biochemistry and Cell Biology, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Bart M. Gadella
- Department of Biochemistry and Cell Biology, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- Department of Farm Animal Health, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- * E-mail:
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Castillo Bennett J, Roggero CM, Mancifesta FE, Mayorga LS. Calcineurin-mediated dephosphorylation of synaptotagmin VI is necessary for acrosomal exocytosis. J Biol Chem 2010; 285:26269-78. [PMID: 20551332 DOI: 10.1074/jbc.m109.095752] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Regulated secretion is a fundamental process underlying the function of many cell types. In particular, acrosomal exocytosis in mammalian sperm is essential for egg fertilization. In general, exocytosis is initiated by a cytosolic calcium increase. In this report we show that calcium affects several factors during human sperm acrosomal exocytosis. By using an antibody that specifically recognizes synaptotagmin VI phosphorylated at the polybasic region of the C2B domain, we showed that a calcium-dependent dephosphorylation of this protein occurred at early stages of the acrosomal exocytosis in streptolysin O-permeabilized sperm. We identified the phosphatase as calcineurin and showed that the activity of this enzyme is absolutely required during the early steps of the secretory process. When added to sperm, an inhibitor-insensitive, catalytically active domain of calcineurin was able to rescue the effect of the specific calcineurin inhibitor cyclosporin A. This same domain dephosphorylated recombinant synaptotagmin VI C2B domain, validating this protein as a new substrate for calcineurin. When sperm were treated with catalytically active calcineurin before stimulation, exocytosis was inhibited, an effect that was rescued by the phosphomimetic synaptotagmin VI C2B-T418E,T419E mutant domain. These observations indicate that synaptotagmin must be dephosphorylated at a specific window of time and suggest that phosphorylated synaptotagmin has an active role at early stages of the acrosomal exocytosis.
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Affiliation(s)
- Jimena Castillo Bennett
- Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
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Hermo L, Pelletier RM, Cyr DG, Smith CE. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 2: changes in spermatid organelles associated with development of spermatozoa. Microsc Res Tech 2010; 73:279-319. [PMID: 19941292 DOI: 10.1002/jemt.20787] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Spermiogenesis is a long process whereby haploid spermatids derived from the meiotic divisions of spermatocytes undergo metamorphosis into spermatozoa. It is subdivided into distinct steps with 19 being identified in rats, 16 in mouse and 8 in humans. Spermiogenesis extends over 22.7 days in rats and 21.6 days in humans. In this part, we review several key events that take place during the development of spermatids from a structural and functional point of view. During early spermiogenesis, the Golgi apparatus forms the acrosome, a lysosome-like membrane bound organelle involved in fertilization. The endoplasmic reticulum undergoes several topographical and structural modifications including the formation of the radial body and annulate lamellae. The chromatoid body is fully developed and undergoes structural and functional modifications at this time. It is suspected to be involved in RNA storing and processing. The shape of the spermatid head undergoes extensive structural changes that are species-specific, and the nuclear chromatin becomes compacted to accommodate the stream-lined appearance of the sperm head. Microtubules become organized to form a curtain or manchette that associates with spermatids at specific steps of their development. It is involved in maintenance of the sperm head shape and trafficking of proteins in the spermatid cytoplasm. During spermiogenesis, many genes/proteins have been implicated in the diverse dynamic events occurring at this time of development of germ cells and the absence of some of these have been shown to result in subfertility or infertility.
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Affiliation(s)
- Louis Hermo
- Faculty of Medicine, Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 2B2.
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35
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Suhaiman L, De Blas GA, Obeid LM, Darszon A, Mayorga LS, Belmonte SA. Sphingosine 1-phosphate and sphingosine kinase are involved in a novel signaling pathway leading to acrosomal exocytosis. J Biol Chem 2010; 285:16302-14. [PMID: 20236935 DOI: 10.1074/jbc.m109.072439] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Regulated secretion is a central issue for the specific function of many cells; for instance, mammalian sperm acrosomal exocytosis is essential for egg fertilization. Sphingosine 1-phosphate is a bioactive sphingolipid that regulates crucial physiological processes. Here we report that this lipid triggers acrosomal exocytosis in human sperm by a mechanism involving a G(i)-coupled receptor. Real-time imaging showed a remarkable increase of cytosolic calcium upon activation with sphingosine 1-phosphate and pharmacological experiments indicate that the process requires extracellular calcium influx through voltage and store-operated calcium channels and efflux from intracellular stores through inositol 1,4,5-trisphosphate-sensitive calcium channels. Sphingosine 1-phosphate-induced exocytosis requires phospholipase C and protein kinase C activation. We investigated possible sources of the lipid. Western blot indicates that sphingosine kinase 1 is present in spermatozoa. Indirect immunofluorescence showed that phorbol ester, a potent protein kinase C activator that can also trigger acrosomal exocytosis, redistributes sphingosine kinase 1 to the acrosomal region. Functional assays showed that phorbol ester-induced exocytosis depends on the activation of sphingosine kinase 1. Furthermore, incorporation of (32)P to sphingosine demonstrates that cells treated with the phorbol ester increase their sphingosine kinase activity that yields sphingosine 1-phosphate. We present here the first evidence indicating that human spermatozoa produce sphingosine 1-phosphate when challenged with an exocytic stimulus. These observations point to a new role of sphingosine 1-phosphate in a signaling cascade that facilitates acrosome reaction providing some clues about novel lipid molecules involved in exocytosis.
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Affiliation(s)
- Laila Suhaiman
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Médicas, CC56, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
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36
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Hu XQ, Ji SY, Li YC, Fan CH, Cai H, Yang JL, Zhang CP, Chen M, Pan ZF, Hu ZY, Gao F, Liu YX. Acrosome formation-associated factor is involved in fertilization. Fertil Steril 2010; 93:1482-92. [DOI: 10.1016/j.fertnstert.2009.01.067] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 01/02/2009] [Accepted: 01/07/2009] [Indexed: 01/15/2023]
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37
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Ackermann F, Zitranski N, Borth H, Buech T, Gudermann T, Boekhoff I. CaMKIIalpha interacts with multi-PDZ domain protein MUPP1 in spermatozoa and prevents spontaneous acrosomal exocytosis. J Cell Sci 2009; 122:4547-57. [PMID: 19934217 DOI: 10.1242/jcs.058263] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The success of acrosomal exocytosis, a complex process with a variety of inter-related steps, relies on the coordinated interaction of participating signaling molecules. Since the acrosome reaction resembles Ca(2+)-regulated exocytosis in neurons, we investigated whether cognate neuronal binding partners of the multi-PDZ domain protein MUPP1, which recruits molecules that control the initial tethering and/or docking between the acrosomal vesicle and the plasma membrane, are also expressed in spermatozoa, and whether they contribute to the regulation of acrosomal secretion. We observed that CaMKIIalpha colocalizes with MUPP1 in the acrosomal region of epididymal spermatozoa where the kinase selectively binds to a region encompassing PDZ domains 10-11 of MUPP1. Furthermore, we found that pre-treating mouse spermatozoa with a CaMKII inhibitor that directly blocks the catalytic region of the kinase, as well as a competitive displacement of CaMKIIalpha from PDZ domains 10-11, led to a significant increase in spontaneous acrosomal exocytosis. Since Ca(2+)-calmodulin releases CaMKIIalpha from the PDZ scaffolding protein, MUPP1 represents a central signaling platform to dynamically regulate the assembly and disassembly of binding partners pertinent to acrosomal secretion, thereby precisely adjusting an increase in Ca(2+) to synchronized fusion pore formation.
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Affiliation(s)
- Frauke Ackermann
- Karolinska Institute, Department of Neuroscience, Stockholm, Sweden
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38
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Zanetti N, Mayorga LS. Acrosomal Swelling and Membrane Docking Are Required for Hybrid Vesicle Formation During the Human Sperm Acrosome Reaction1. Biol Reprod 2009; 81:396-405. [DOI: 10.1095/biolreprod.109.076166] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Sousa APM, Gomes-Santos CSS, Ramalho-Santos J. LOCALIZATION OF SNARES, NSF AND CAVEOLIN 1 IN HUMAN SPERMATOZOA: RELATIONSHIP WITH SEMINAL PARAMETERS. ACTA ACUST UNITED AC 2009; 52:347-53. [PMID: 16873134 DOI: 10.1080/01485010600667050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Membrane fusion is a very important process in gametes. The mechanism of membrane fusion during the AR has been proposed to involve SNAREs. Our aim is to quantify patterns of localization of Caveolin 1, SNAREs (Syntaxin 1A, Syntaxin 2 and VAMP 1) and NSF on human sperm, to determine how the differential distribution of these proteins might be interdependent and to evaluate if this distribution is related with seminal parameters. These proteins are present in different regions of the head of human sperm: anterior, equatorial and posterior regions and that Syntaxin 2 and Syntaxin 1A had a slightly different pattern of labelling. The presence and localization of SNAREs, NSF and Caveolin 1 do not correlate with seminal parameters. There is significant correlation between NSF and SNAREs, which may indicate a cooperation of these proteins in membrane fusion mechanisms of human sperm.
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Affiliation(s)
- A P M Sousa
- Department of Zoology, Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
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Ramalho-Santos J, Schatten G. PRESENCE OF N-ETHYL MALEIMIDE SENSITIVE FACTOR (NSF) ON THE ACROSOME OF MAMMALIAN SPERM. ACTA ACUST UNITED AC 2009; 50:163-8. [PMID: 15204682 DOI: 10.1080/01485010490425502] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We have extended previous observations to show that the ATPase N-ethyl maleimide sensitive factor (NSF) an important regulator of membrane trafficking and fusion in somatic cells, is present on bovine, murine and rhesus macaque sperm. However, NSFs main effectors, alfa- and beta-SNAP, although present in the developing acrosome, could not be detected in the mature organelle. The fact that NSF localizes mainly to the acrosome suggests that this protein, together with other factors such as rabs and SNAREs, may be a common feature in the triggering/regulation of membrane merging during the mammalian acrosome reaction.
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Affiliation(s)
- J Ramalho-Santos
- Pittsburgh Development Center, Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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41
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Tsai PS, De Vries KJ, De Boer-Brouwer M, Garcia-Gil N, Van Gestel RA, Colenbrander B, Gadella BM, Van Haeften T. Syntaxin and VAMP association with lipid rafts depends on cholesterol depletion in capacitating sperm cells. Mol Membr Biol 2009; 24:313-24. [PMID: 17520487 DOI: 10.1080/09687860701228692] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Sperm cells represent a special exocytotic system since mature sperm cells contain only one large secretory vesicle, the acrosome, which fuses with the overlying plasma membrane during the fertilization process. Acrosomal exocytosis is believed to be regulated by activation of SNARE proteins. In this paper, we identified specific members of the SNARE protein family, i.e., the t-SNAREs syntaxin1 and 2, and the v-SNARE VAMP, present in boar sperm cells. Both syntaxins were predominantly found in the plasma membrane whereas v-SNAREs are mainly located in the outer acrosomal membrane of these cells. Under non-capacitating conditions both syntaxins and VAMP are scattered in well-defined punctate structures over the entire sperm head. Bicarbonate-induced in vitro activation in the presence of BSA causes a relocalization of these SNAREs to a more homogeneous distribution restricted to the apical ridge area of the sperm head, exactly matching the site of sperm zona binding and subsequent induced acrosomal exocytosis. This redistribution of syntaxin and VAMP depends on cholesterol depletion and closely resembles the previously reported redistribution of lipid raft marker proteins. Detergent-resistant membrane isolation and subsequent analysis shows that a significant proportion of syntaxin emerges in the detergent-resistant membrane (raft) fraction under such conditions, which is not the case under those conditions where cholesterol depletion is blocked. The v-SNARE VAMP displays a similar cholesterol depletion-dependent lateral and raft redistribution. Taken together, our results indicate that redistribution of syntaxin and VAMP during capacitation depends on association of these SNAREs with lipid rafts and that such a SNARE-raft association may be essential for spatial control of exocytosis and/or regulation of SNARE functioning.
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Affiliation(s)
- Pei-Shiue Tsai
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University. Utrecht. The Netherlands
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42
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Branham MT, Bustos MA, De Blas GA, Rehmann H, Zarelli VEP, Treviño CL, Darszon A, Mayorga LS, Tomes CN. Epac activates the small G proteins Rap1 and Rab3A to achieve exocytosis. J Biol Chem 2009; 284:24825-39. [PMID: 19546222 DOI: 10.1074/jbc.m109.015362] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Exocytosis of the acrosome (the acrosome reaction) relies on cAMP production, assembly of a proteinaceous fusion machinery, calcium influx from the extracellular medium, and mobilization from inositol 1,4,5-trisphosphate-sensitive intracellular stores. Addition of cAMP to human sperm suspensions bypasses some of these requirements and elicits exocytosis in a protein kinase A- and extracellular calcium-independent manner. The relevant cAMP target is Epac, a guanine nucleotide exchange factor for the small GTPase Rap. We show here that a soluble adenylyl cyclase synthesizes the cAMP required for the acrosome reaction. Epac stimulates the exchange of GDP for GTP on Rap1, upstream of a phospholipase C. The Epac-selective cAMP analogue 8-pCPT-2'-O-Me-cAMP induces a phospholipase C-dependent calcium mobilization in human sperm suspensions. In addition, our studies identify a novel connection between cAMP and Rab3A, a secretory granule-associated protein, revealing that the latter functions downstream of soluble adenylyl cyclase/cAMP/Epac but not of Rap1. Challenging sperm with calcium or 8-pCPT-2'-O-Me-cAMP boosts the exchange of GDP for GTP on Rab3A. Recombinant Epac does not release GDP from Rab3A in vitro, suggesting that the Rab3A-GEF activation by cAMP/Epac in vivo is indirect. We propose that Epac sits at a critical point during the exocytotic cascade after which the pathway splits into two limbs, one that assembles the fusion machinery into place and another that elicits intracellular calcium release.
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Affiliation(s)
- María T Branham
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Médicas, CC 56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina
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43
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Zarelli VEP, Ruete MC, Roggero CM, Mayorga LS, Tomes CN. PTP1B dephosphorylates N-ethylmaleimide-sensitive factor and elicits SNARE complex disassembly during human sperm exocytosis. J Biol Chem 2009; 284:10491-503. [PMID: 19208619 PMCID: PMC2667736 DOI: 10.1074/jbc.m807614200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 01/28/2009] [Indexed: 11/06/2022] Open
Abstract
The reversible phosphorylation of tyrosyl residues in proteins is a cornerstone of the signaling pathways that regulate numerous cellular responses. Protein tyrosine phosphorylation is controlled through the concerted actions of protein-tyrosine kinases and phosphatases. The goal of the present study was to unveil the mechanisms by which protein tyrosine dephosphorylation modulates secretion. The acrosome reaction, a specialized type of regulated exocytosis undergone by sperm, is initiated by calcium and carried out by a number of players, including tyrosine kinases and phosphatases, and fusion-related proteins such as Rab3A, alpha-SNAP, N-ethylmaleimide-sensitive factor (NSF), SNAREs, complexin, and synaptotagmin VI. We report here that inducers were unable to elicit the acrosome reaction when permeabilized human sperm were loaded with anti-PTP1B antibodies or with the dominant-negative mutant PTP1B D181A; subsequent introduction of wild type PTP1B or NSF rescued exocytosis. Wild type PTP1B, but not PTP1B D181A, caused cis SNARE complex dissociation during the acrosome reaction through a mechanism involving NSF. Unlike its non-phosphorylated counterpart, recombinant phospho-NSF failed to dissociate SNARE complexes from rat brain membranes. These results strengthen our previous observation that NSF activity is regulated rather than constitutive during sperm exocytosis and indicate that NSF must be dephosphorylated by PTP1B to disassemble SNARE complexes. Interestingly, phospho-NSF served as a substrate for PTP1B in an in vitro assay. Our findings demonstrate that phosphorylation of NSF on tyrosine residues prevents its SNARE complex dissociation activity and establish for the first time a role for PTP1B in the modulation of the membrane fusion machinery.
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Affiliation(s)
- Valeria E P Zarelli
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM-CONICET), Facultad de Ciencias Médicas, CC 56, Universidad Nacional de Cuyo, 5500 Mendoza, Argentina
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44
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Yuksel B, Memon AR. Comparative phylogenetic analysis of small GTP-binding genes of model legume plants and assessment of their roles in root nodules. JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:3831-44. [PMID: 18849296 PMCID: PMC2576638 DOI: 10.1093/jxb/ern223] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 07/17/2008] [Accepted: 08/06/2008] [Indexed: 05/03/2023]
Abstract
Small GTP-binding genes play an essential regulatory role in a multitude of cellular processes such as vesicle-mediated intracellular trafficking, signal transduction, cytoskeletal organization, and cell division in plants and animals. Medicago truncatula and Lotus japonicus are important model plants for studying legume-specific biological processes such as nodulation. The publicly available online resources for these plants from websites such as http://www.ncbi.nih.gov, http://www.medicago.org, http://www.tigr.org, and related sites were searched to collect nucleotide sequences that encode GTP-binding protein homologues. A total of 460 small GTPase sequences from several legume species including Medicago and Lotus, Arabidopsis, human, and yeast were phyletically analysed to shed light on the evolution and functional characteristics of legume-specific homologues. One of the main emphases of this study was the elucidation of the possible involvement of some members of small GTPase homologues in the establishment and maintenance of symbiotic associations in root nodules of legumes. A high frequency of vesicle-mediated trafficking in nodules led to the idea of a probable subfunctionalization of some members of this family in legumes. As a result of the analyses, a group of 10 small GTPases that are likely to be mainly expressed in nodules was determined. The sequences determined as a result of this study could be used in more detailed molecular genetic analyses such as creation of RNA interference silencing mutants for further clarification of the role of GTPases in nodulation. This study will also assist in furthering our understanding of the evolutionary history of small GTPases in legume species.
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Affiliation(s)
- Bayram Yuksel
- Plant Molecular Biology Laboratory, Genetic Engineering and Biotechnology Institute, Marmara Research Center, TUBITAK, PO Box 21, 41400, Gebze, Kocaeli, Turkey.
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45
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Mountjoy JR, Xu W, McLeod D, Hyndman D, Oko R. RAB2A: A Major Subacrosomal Protein of Bovine Spermatozoa Implicated in Acrosomal Biogenesis1. Biol Reprod 2008; 79:223-32. [DOI: 10.1095/biolreprod.107.065060] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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46
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Zhao L, Burkin HR, Shi X, Li L, Reim K, Miller DJ. Complexin I is required for mammalian sperm acrosomal exocytosis. Dev Biol 2007; 309:236-44. [PMID: 17692307 PMCID: PMC2099451 DOI: 10.1016/j.ydbio.2007.07.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 07/10/2007] [Accepted: 07/12/2007] [Indexed: 12/17/2022]
Abstract
Regulated exocytosis in many cells is controlled by the SNARE complex, whose core includes three proteins that promote membrane fusion. Complexins I and II are highly related cytosolic proteins that bind tightly to the assembled SNARE complex and regulate neuronal exocytosis. Like somatic cells, sperm undergo regulated exocytosis; however, sperm release a single large vesicle, the acrosome, whose release has different characteristics than neuronal exocytosis. Acrosomal release is triggered upon sperm adhesion to the mammalian egg extracellular matrix (zona pellucida) to allow penetration of the egg coat. Membrane fusion occurs at multiple points within the acrosome but how fusion is activated and the formation and progression of fusion points is synchronized is unclear. We show that complexins I and II are found in acrosome-intact mature sperm, bind to SNARE complex proteins, and are not detected in sperm after acrosomal exocytosis (acrosome reaction). Although complexin-I-deficient sperm acrosome-react in response to calcium ionophore, they do not acrosome-react in response to egg zona pellucida proteins and have reduced fertilizing ability, in vitro. Complexin II is present in the complexin-I-deficient sperm and its expression is increased in complexin-I-deficient testes. Therefore, complexin I functions in exocytosis in two related but morphologically distinct secretory processes. Sperm are unusual because they express both complexins I and II but have a unique and specific requirement for complexin I.
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Affiliation(s)
- Longmei Zhao
- University of Illinois, Department of Animal Sciences, 1207 West Gregory Drive, Urbana, Illinois 61801
| | - Heather R. Burkin
- University of Illinois, Department of Animal Sciences, 1207 West Gregory Drive, Urbana, Illinois 61801
| | - Xudong Shi
- University of Illinois, Department of Animal Sciences, 1207 West Gregory Drive, Urbana, Illinois 61801
| | - Lingjun Li
- University of Wisconsin, School of Pharmacy, 777 Highland Avenue, Madison, Wisconsin 53705
| | - Kerstin Reim
- Max-Plank-Institute for Experimental Medicine, Department of Molecular Neurobiology, D-37075 Göttingen, Germany
| | - David J. Miller
- University of Illinois, Department of Animal Sciences, 1207 West Gregory Drive, Urbana, Illinois 61801
- Correspondence should be addressed to: David J. Miller, University of Illinois, 1207 West Gregory Drive, Urbana, Illinois 61801, Tel: (217) 333-3408, Fax: (217) 333-8286, e-mail:
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47
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Lopez CI, Belmonte SA, De Blas GA, Mayorga LS. Membrane-permeant Rab3A triggers acrosomal exocytosis in living human sperm. FASEB J 2007; 21:4121-30. [PMID: 17625073 DOI: 10.1096/fj.06-7716com] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The acrosome reaction is a regulated Ca2+-dependent secretion event required for sperm-egg interaction. Previous studies indicate that the process requires Rab3-dependent tethering of membranes, SNARE complex assembly, and Ca2+-mediated activation of synaptotagmin. Sperm are transcriptionally and translationally inactive; hence, most studies of the exocytosis mechanism are limited to membrane-permeant reagents. The effect of proteins involved in exocytosis has been assessed only in permeabilized cells. Polyarginine peptides are a powerful tool for delivering macromolecules to cells. Most reports indicate that membrane translocation of arginine-containing proteins requires endocytosis; therefore, this strategy might not be useful in sperm. However, our results indicate that GST and Rab3A, when fused with an arginine-rich peptide, were able to translocate into sperm. Moreover, membrane-permeant Rab3A initiated exocytosis when prenylated and activated with GTP. We show here that a key event after the cytoplasmic Ca2+ increase caused by progesterone is the activation of Rab3A. When active Rab3A is introduced into sperm, Ca2+ in the extracellular medium and in the cytoplasm is dispensable. However, a Ca2+ efflux from inside the acrosome is still required to achieve exocytosis. In conclusion, arginine-containing proteins can penetrate the sperm plasma membrane and thus are valuable tools to study sperm physiology in intact cells.
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Affiliation(s)
- Cecilia I Lopez
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
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48
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Roggero CM, De Blas GA, Dai H, Tomes CN, Rizo J, Mayorga LS. Complexin/synaptotagmin interplay controls acrosomal exocytosis. J Biol Chem 2007; 282:26335-43. [PMID: 17613520 DOI: 10.1074/jbc.m700854200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulated secretion is a fundamental process underlying the function of many cell types. In particular, acrosomal exocytosis in mammalian sperm is essential for egg fertilization. Regulated secretion requires SNARE proteins and, in neurons, also synaptotagmin I and complexin. Recent reports suggest that complexin imposes a fusion block that is released by Ca(2+) and synaptotagmin I. However, no direct evidence for this model in secreting cells has been provided and whether this complexin/synaptotagmin interplay functions in other types of secretion is unknown. In this report, we show that the C2B domain of synaptotagmin VI and an anti-complexin antibody blocked the formation of trans SNARE complexes in permeabilized human sperm, and that this effect was reversed by adding complexin. In contrast, an excess of complexin stopped exocytosis at a later step, when SNAREs were assembled in loose trans complexes. Interestingly, this blockage was released by the addition of the synaptotagmin VI C2B domain in the presence of Ca(2+). We have previously demonstrated that the activity of this domain is regulated by protein kinase C-mediated phosphorylation. Here, we show that a phosphomimetic mutation in the polybasic region of the C2B domain strongly affects its Ca(2+) and phospholipids binding properties. Importantly, this mutation completely abrogates its ability to rescue the complexin block. Our results show that the functional interplay between complexin and synaptotagmin has a central role in a physiological secretion event, and that this interplay can be modulated by phosphorylation of the C2B domain.
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Affiliation(s)
- Carlos M Roggero
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
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Ducibella T, Matson S. Secretory mechanisms and Ca2+ signaling in gametes: similarities to regulated neuroendocrine secretion in somatic cells and involvement in emerging pathologies. Endocr Pathol 2007; 18:191-203. [PMID: 18247164 DOI: 10.1007/s12022-007-0015-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Recent studies demonstrate that regulated secretion in probably all mammalian cells, from gonadotropes to gametes, utilizes similar signaling systems, intracellular Ca(2+) regulation, Ca(2+)-dependent proteins, cytoskeletal participation, and SNARE-mediated fusion. Thus, highly specialized cells, like sperm and eggs, should no longer be considered to have evolved a cell-type specific secretory mechanism. In gametes, Ca(2+)-dependent proteins and enzymes transduce elevations of intracellular Ca(2+) into secretory events, i.e., exocytosis of the acrosome in sperm and cortical granules in the egg. Just as secretory deficiencies have clinical consequences in endocrine and exocrine cells, failure of secretion of cortical granules or the acrosome can result in failure of normal fertilization or fertilization followed by abnormal development. With the advent of human in vitro fertilization, such gamete pathologies have been recently identified and have led to new clinical procedures to achieve normal fertilization and pregnancies. A better understanding of the common Ca(2+)-dependent secretory pathways in both gametes and somatic cells should be beneficial to investigating mis-regulation in either cell type.
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Affiliation(s)
- Tom Ducibella
- Sackler School of Biomedical Sciences, Program in Cell, Molecular, and Developmental Biology, Tufts University School of Medicine, Boston, MA, 0211, USA.
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50
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Choi J, Richards KL, Cinar HN, Newman AP. N-ethylmaleimide sensitive factor is required for fusion of the C. elegans uterine anchor cell. Dev Biol 2006; 297:87-102. [PMID: 16769048 DOI: 10.1016/j.ydbio.2006.04.471] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 04/27/2006] [Accepted: 04/28/2006] [Indexed: 01/17/2023]
Abstract
The fusion of the Caenorhabditis elegans uterine anchor cell (AC) with the uterine-seam cell (utse) is an excellent model system for studying cell-cell fusion, which is essential to animal development. We obtained an egg-laying defective (Egl) mutant in which the AC fails to fuse with the utse. This defect is highly specific: other aspects of utse development and other cell fusions appear to occur normally. We find that defect is due to a missense mutation in the nsf-1 gene, which encodes N-ethylmaleimide-sensitive factor (NSF), an intracellular membrane fusion factor. There are two NSF-1 isoforms, which are expressed in distinct tissues through two separate promoters. NSF-1L is expressed in the uterus, including the AC. We find that nsf-1 is required cell-autonomously in the AC for its fusion with the utse. Our results establish AC fusion as a paradigm for studying cell fusion at single cell resolution and demonstrate that the NSF ATPase is a key player in this process.
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Affiliation(s)
- Jaebok Choi
- Verna and Marrs Maclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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