scholarly journals Egg cortical granule N-acetylglucosaminidase is required for the mouse zona block to polyspermy.

1993 ◽  
Vol 123 (6) ◽  
pp. 1431-1440 ◽  
Author(s):  
D J Miller ◽  
X Gong ◽  
G Decker ◽  
B D Shur
Keyword(s):  
Zona Pellucida ◽  
Binding Sites ◽  
Binding Activity ◽  
Cortical Granule ◽  
Cortical Granules ◽  
Sperm Binding ◽  
Competitive Inhibitors ◽  
Glycosidase Inhibitor ◽  
Egg Coat

The mammalian egg must be fertilized by only one sperm to prevent polyploidy. In most mammals studied to date, the primary block to polyspermy occurs at the zona pellucida, the mammalian egg coat, after exocytosis of the contents of the cortical granules into the perivitelline space. The exudate acts on the zona, causing it to lose its ability to bind sperm and to be penetrated by sperm previously bound to the zona. However, the cortical granule components responsible for the zona block have not been identified. Studies described herein demonstrate that N-acetylglucosaminidase is localized in cortical granules and is responsible for the loss in sperm-binding activity leading to the zona block to polyspermy. Before fertilization, sperm initially bind to the zona by an interaction between sperm surface GalTase and terminal N-acetylglucosamine residues on specific oligosaccharides of the zona glycoprotein ZP3 (Miller, D. J., M. B. Macek, and B. D. Shur. 1992. Nature (Lond.). 357:589-593). These GalTase-binding sites are lost from ZP3 after fertilization, an effect that can be duplicated by N-acetylglucosaminidase treatment. Therefore, N-acetylglucosaminidase, or a related glycosidase, may be present in cortical granules and be responsible for ZP3's loss of sperm-binding activity at fertilization. Of eight glycosidases assayed in exudates of ionophore-activated eggs, N-acetylglucosaminidase was 10-fold higher than any other activity. The enzyme was localized to cortical granules using immunoelectron microscopy. Approximately 70 or 90% of the enzyme was released from cortical granules after ionophore activation or in vivo fertilization, respectively. The isoform of N-acetylglucosaminidase found in cortical granules was identified as beta-hexosaminidase B, the beta, beta homodimer. Inhibition of N-acetylglucosaminidase released from activated eggs, with either competitive inhibitors or with specific antibodies, resulted in polyspermic binding to the zona pellucida. Another glycosidase inhibitor or nonimmune antibodies had no effect on sperm binding to activated eggs. Therefore, egg cortical granule N-acetylglucosaminidase is released at fertilization, where it inactivates the sperm GalTase-binding site, accounting for the block in sperm binding to the zona pellucida.

scholarly journals Identification of Sperm-Binding Sites in the N-Terminal Domain of Bovine Egg Coat Glycoprotein ZP4

2022 ◽  
Vol 23 (2) ◽  
pp. 762
Author(s):  
Kamila Dilimulati ◽  
Misaki Orita ◽  
Yoshiki Yonahara ◽  
Fabiana Lica Imai ◽  
Naoto Yonezawa
Keyword(s):  
Binding Sites ◽  
Binding Activity ◽  
Binding Region ◽  
Terminal Domain ◽  
Sperm Binding ◽  
Bovine Sperm ◽  
Selective Interaction ◽  
Egg Coat

The species-selective interaction between sperm and egg at the beginning of mammalian fertilisation is partly mediated by a transparent envelope called the zona pellucida (ZP). The ZP is composed of three or four glycoproteins (ZP1–ZP4). The functions of the three proteins present in mice (ZP1–ZP3) have been extensively studied. However, the biological role of ZP4, which was found in all other mammals studied so far, has remained largely unknown. Previously, by developing a solid support assay system, we showed that ZP4 exhibits sperm-binding activity in bovines and the N-terminal domain of bovine ZP4 (bZP4 ZP-N1 domain) is a sperm-binding region. Here, we show that bovine sperm bind to the bZP4 ZP-N1 domain in a species-selective manner and that N-glycosylation is not required for sperm-binding activity. Moreover, we identified three sites involved in sperm binding (site I: from Gln-41 to Pro-46, site II: from Leu-65 to Ser-68 and site III: from Thr-108 to Ile-123) in the bZP4 ZP-N1 domain using chimeric bovine/porcine and bovine/human ZP4 recombinant proteins. These results provide in vitro experimental evidence for the role of the bZP4 ZP-N1 domain in mediating sperm binding to the ZP.

scholarly journals Sperm-binding regions on bovine egg zona pellucida glycoprotein ZP4 studied in a solid supported form on plastic plate

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254234
Author(s):  
Kamila Dilimulati ◽  
Misaki Orita ◽  
Ganbat Undram ◽  
Naoto Yonezawa
Keyword(s):  
Zona Pellucida ◽  
Binding Sites ◽  
Insect Cells ◽  
Competitive Inhibition ◽  
Expression System ◽  
Binding Activity ◽  
Mammalian Oocyte ◽  
Sperm Binding ◽  
Bovine Sperm ◽  
Binding Mechanisms

The zona pellucida (ZP) is a transparent envelope that surrounds the mammalian oocyte and mediates species-selective sperm–oocyte interactions. The bovine ZP consists of the glycoproteins ZP2, ZP3, and ZP4. Sperm-binding mechanisms of the bovine ZP are not yet fully elucidated. In a previous report, we established the expression system of bovine ZP glycoproteins using Sf9 insect cells and found that the ZP3/ZP4 heterocomplex inhibits the binding of sperm to the ZP in a competitive inhibition assay, while ZP2, ZP3, ZP4, the ZP2/ZP3 complex, and the ZP2/ZP4 complex do not exhibit this activity. Here, we show that bovine sperm binds to plastic plates coated with ZP4 in the absence of ZP3. We made a series of ZP4 deletion mutants to study the sperm-binding sites. The N-terminal region, Lys-25 to Asp-136, and the middle region, Ser-290 to Lys-340, of ZP4 exhibit sperm-binding activity. These results suggest that among the three components of bovine ZP glycoproteins, ZP4 contains the major potential sperm-binding sites, and the formation of a multivalent complex is necessary for the sperm-binding activity of ZP4.

scholarly journals Ovastacin, a cortical granule protease, cleaves ZP2 in the zona pellucida to prevent polyspermy

2012 ◽  
Vol 197 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Anna D. Burkart ◽  
Bo Xiong ◽  
Boris Baibakov ◽  
Maria Jiménez-Movilla ◽  
Jurrien Dean
Keyword(s):  
Zona Pellucida ◽  
Cleavage Site ◽  
Single Copy ◽  
Cortical Granule ◽  
Cortical Granules ◽  
Successful Development ◽  
Mouse Sperm ◽  
Subcellular Organelles ◽  
Sperm Binding ◽  
Definitive Role

The mouse zona pellucida is composed of three glycoproteins (ZP1, ZP2, and ZP3), of which ZP2 is proteolytically cleaved after gamete fusion to prevent polyspermy. This cleavage is associated with exocytosis of cortical granules that are peripherally located subcellular organelles unique to ovulated eggs. Based on the cleavage site of ZP2, ovastacin was selected as a candidate protease. Encoded by the single-copy Astl gene, ovastacin is an oocyte-specific member of the astacin family of metalloendoproteases. Using specific antiserum, ovastacin was detected in cortical granules before, but not after, fertilization. Recombinant ovastacin cleaved ZP2 in native zonae pellucidae, documenting that ZP2 was a direct substrate of this metalloendoprotease. Female mice lacking ovastacin did not cleave ZP2 after fertilization, and mouse sperm bound as well to Astl-null two-cell embryos as they did to normal eggs. Ovastacin is a pioneer component of mouse cortical granules and plays a definitive role in the postfertilization block to sperm binding that ensures monospermic fertilization and successful development.

scholarly journals Cryo-EM Structure of Native Human Uromodulin, a Zona Pellucida Module Polymer

2020 ◽  
Author(s):  
Alena Stsiapanava ◽  
Chenrui Xu ◽  
Martina Brunati ◽  
Sara Zamora-Caballero ◽  
Céline Schaeffer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Zona Pellucida ◽  
Binding Sites ◽  
Lateral Interaction ◽  
Biological Processes ◽  
Binding Region ◽  
Sperm Binding ◽  
Cryo Electron Microscopy ◽  
Uropathogenic Bacteria ◽  
Egg Coat

SUMMARYAssembly of extracellular filaments and matrices mediating fundamental biological processes such as morphogenesis, hearing, fertilization and antibacterial defense is driven by a ubiquitous polymerization module known as zona pellucida (ZP) “domain”. Despite the conservation of this element from hydra to human, no information is available on the filamentous conformation of any ZP module protein. Here we report the cryo-electron microscopy structure of uromodulin (UMOD)/Tamm-Horsfall protein, the most abundant protein in human urine and an archetypal ZP module-containing molecule, in its mature homopolymeric state. UMOD forms a one-start helix with an unprecedented 180-degree twist between subunits enfolded by interdomain linkers that have completely reorganized as a result of propeptide dissociation. Lateral interaction between filaments in the urine generates sheets exposing a checkerboard of binding sites to capture uropathogenic bacteria, and UMOD-based models of mammalian and avian heteromeric egg coat filaments identify a common sperm-binding region at the interface between subunits.

RAP1 is required for BAS1/BAS2- and GCN4-dependent transcription of the yeast HIS4 gene

1991 ◽  
Vol 11 (7) ◽  
pp. 3642-3651 ◽  
Author(s):  
C Devlin ◽  
K Tice-Baldwin ◽  
D Shore ◽  
K T Arndt
Keyword(s):  
Steady State ◽  
Binding Site ◽  
Binding Sites ◽  
Binding Activity ◽  
Micrococcal Nuclease ◽  
Mrna Levels ◽  
High Affinity ◽  
Steady State Levels

The major in vitro binding activity to the Saccharomyces cerevisiae HIS4 promoter is due to the RAP1 protein. In the absence of GCN4, BAS1, and BAS2, the RAP1 protein binds to the HIS4 promoter in vivo but cannot efficiently stimulate HIS4 transcription. RAP1, which binds adjacently to BAS2 on the HIS4 promoter, is required for BAS1/BAS2-dependent activation of HIS4 basal-level transcription. In addition, the RAP1-binding site overlaps with the single high-affinity HIS4 GCN4-binding site. Even though RAP1 and GCN4 bind competitively in vitro, RAP1 is required in vivo for (i) the normal steady-state levels of GCN4-dependent HIS4 transcription under nonstarvation conditions and (ii) the rapid increase in GCN4-dependent steady-state HIS4 mRNA levels following amino acid starvation. The presence of the RAP1-binding site in the HIS4 promoter causes a dramatic increase in the micrococcal nuclease sensitivity of two adjacent regions within HIS4 chromatin: one region contains the high-affinity GCN4-binding site, and the other region contains the BAS1- and BAS2-binding sites. These results suggest that RAP1 functions at HIS4 by increasing the accessibility of GCN4, BAS1, and BAS2 to their respective binding sites when these sites are present within chromatin.

scholarly journals A single domain of the ZP2 zona pellucida protein mediates gamete recognition in mice and humans

2014 ◽  
Vol 205 (6) ◽  
pp. 801-809 ◽  
Author(s):  
Matteo A. Avella ◽  
Boris Baibakov ◽  
Jurrien Dean
Keyword(s):  
Transgenic Mice ◽  
Zona Pellucida ◽  
Human Sperm ◽  
Recombinant Peptide ◽  
Genetic Ablation ◽  
Sperm Binding ◽  
Gamete Recognition ◽  
Mammalian Fertilization ◽  
Human And Mouse

The extracellular zona pellucida surrounds ovulated eggs and mediates gamete recognition that is essential for mammalian fertilization. Zonae matrices contain three (mouse) or four (human) glycoproteins (ZP1–4), but which protein binds sperm remains controversial. A defining characteristic of an essential zona ligand is sterility after genetic ablation. We have established transgenic mice expressing human ZP4 that form zonae pellucidae in the absence of mouse or human ZP2. Neither mouse nor human sperm bound to these ovulated eggs, and these female mice were sterile after in vivo insemination or natural mating. The same phenotype was observed with truncated ZP2 that lacks a restricted domain within ZP251–149. Chimeric human/mouse ZP2 isoforms expressed in transgenic mice and recombinant peptide bead assays confirmed that this region accounts for the taxon specificity observed in human–mouse gamete recognition. These observations in transgenic mice document that the ZP251–149 sperm-binding domain is necessary for human and mouse gamete recognition and penetration through the zona pellucida.

scholarly journals Insights into the molecular basis of sperm–egg recognition in mammals

Reproduction ◽  
2004 ◽  
Vol 127 (4) ◽  
pp. 417-422 ◽  
Author(s):  
Tanya Hoodbhoy ◽  
Jurrien Dean
Keyword(s):  
Zona Pellucida ◽  
Three Dimensional ◽  
Explanatory Models ◽  
Dimensional Structure ◽  
Side Chain ◽  
Egg Recognition ◽  
Three Dimensional Structure ◽  
Sperm Binding ◽  
Single Protein

The zona pellucida surrounding the egg and pre-implantation embryo is required for in vivo fertility and early development. Explanatory models of sperm–egg recognition need to take into account the ability of sperm to bind to ovulated eggs, but not to two-cell embryos. For the last two decades, investigators have sought to identify an individual protein or carbohydrate side chain as the ‘sperm receptor’. However, recent genetic data in mice are more consistent with the three-dimensional structure of the zona pellucida, rather than a single protein (or carbohydrate), determining sperm binding. The mouse and human zonae pellucidae contain three glycoproteins (ZP1, ZP2, ZP3) and, following fertilization, ZP2 is proteolytically cleaved. The replacement of endogenous mouse proteins with human ZP2, ZP3 or both does not alter taxon specificity of sperm binding or prevent fertility. Surprisingly, human ZP2 is not cleaved following fertilization and intact ZP2 correlates with persistent sperm binding to two-cell embryos. Taken together, these data support a model in which the cleavage status of ZP2 modulates the three-dimensional structure of the zona pellucida and determines whether sperm bind (uncleaved) or do not (cleaved).

scholarly journals Functional Characterization of a Novel Ku70/80 Pause Site at the H19/Igf2 Imprinting Control Region

2005 ◽  
Vol 25 (10) ◽  
pp. 3855-3863 ◽  
Author(s):  
David J. Katz ◽  
Michael A. Beer ◽  
John M. Levorse ◽  
Shirley M. Tilghman
Keyword(s):  
Binding Sites ◽  
Zinc Finger Protein ◽  
Functional Characterization ◽  
Binding Activity ◽  
Mobility Shift ◽  
Control Center ◽  
Dna Binding Activity ◽  
A Genome ◽  
Pause Site

ABSTRACT The imprinted expression of the H19 and Igf2 genes in the mouse is controlled by an imprinting control center (ICR) whose activity is regulated by parent-of-origin differences in methylation. The only protein that has been implicated in ICR function is the zinc-finger protein CTCF, which binds at multiple sites within the maternally inherited ICR and is required to form a chromatin boundary that inhibits Igf2 expression. To identify other proteins that play a role in imprinting, we employed electrophoresis mobility shift assays to identify two novel binding sites within the ICR. The DNA binding activity was identified as the heterodimer Ku70/80, which binds nonspecifically to free DNA ends. The sites within the ICR bind Ku70/80 in a sequence-specific manner and with higher affinity than previously reported binding sites. The binding required the presence of Mg2+, implying that the sequence is a pause site for Ku70/80 translocation from a free end. Chromatin immunoprecipitation assays were unable to confirm that Ku70/80 binds to the ICR in vivo. In addition, mutation of these binding sites in the mouse did not result in any imprinting defects. A genome scan revealed that the binding site is found in LINE-1 retrotransposons, suggesting a possible role for Ku70/80 in transposition.

scholarly journals Variations in modifications of sugar residues in hamster zona pellucida after in vivo fertilization and in vitro egg activation

Reproduction ◽  
2002 ◽  
pp. 671-682 ◽  
Author(s):  
M El-Mestrah ◽  
FW Kan
Keyword(s):  
Quantitative Analysis ◽  
Zona Pellucida ◽  
Hydrolytic Enzymes ◽  
Outer Region ◽  
Egg Activation ◽  
Cortical Granules ◽  
Neuraminidase Treatment ◽  
Thin Sections

Lectins were used as probes in conjunction with quantitative analysis to investigate the distribution of different carbohydrate residues in hamster zona pellucida and their possible modification patterns after in vivo fertilization and in vitro egg activation. Several lectins including HPA, WGA, RCA-I, PNA, DSA, BSAIB(4), DBA, AAA and MAA were used to label the zona pellucida of both unfertilized and fertilized eggs. With the exception of PNA and BSAIB(4), the same lectins were also used to label the zona pellucida of oocytes activated in vitro. A multicomparison quantitative analysis of the density of labelling in the inner and outer regions of the zona pellucida before and after fertilization in vivo, as well as after in vitro egg activation, was performed. Of all the lectins studied, preferential localization of labelling by RCA-I and DSA to the inner zona pellucida of unfertilized eggs was observed. After in vivo fertilization, there was an increase in labelling in the inner region of the zona pellucida when thin sections of fertilized oocytes were incubated with HPA, BSAIB(4) and AAA. Although increased labelling by RCA-I was observed, a significant decrease in labelling intensity was obtained with WGA and the sequence Neu-WGA in both the inner and outer zona pellucida of fertilized oocytes. A significant increase in the density of labelling with WGA was also observed after digestion with neuraminidase. In parallel, when hamster oocytes activated in vitro were compared with those fertilized in vivo, a difference in lectin-gold labelling was observed in both the inner and outer region of the zona pellucida. Labelling with HPA, WGA, DSA and MAA increased significantly in both the inner and outer regions of the zona pellucida, whereas labelling by DBA significantly decreased in the inner portion of the zona pellucida. After neuraminidase treatment, a significant increase in labelling density was observed when thin sections of in vitro-activated oocytes were incubated with WGA. These results demonstrate: (i) the post-fertilization modifications of major saccharidic determinants that may play a role in the sperm-egg interaction process of fertilization in vivo; and (ii) that the modified properties of zonae pellucidae of fertilized and in vitro-activated eggs resulting from the action of hydrolytic enzymes, as well as glycoproteins released through exocytosis of cortical granules, are not identical.

Zona pellucida characteristics and sperm-binding patterns of in vivo and in vitro produced porcine oocytes inseminated with differently prepared spermatozoa

2005 ◽  
Vol 63 (2) ◽  
pp. 352-362 ◽  
Author(s):  
Detlef Rath ◽  
Edda Töpfer-Petersen ◽  
Hans-Wilhelm Michelmann ◽  
Peter Schwartz ◽  
Silja Ebeling
Keyword(s):  
Zona Pellucida ◽  
Sperm Binding
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