Dicalcin inhibits fertilization through its binding to a glycoprotein in the egg envelope in Xenopus laevis.
نویسندگان
چکیده
Fertilization comprises oligosaccharide-mediated sperm-egg interactions, including sperm binding to an extracellular egg envelope, sperm penetration through the envelope, and fusion with an egg plasma membrane. We show that Xenopus dicalcin, an S100-like Ca(2+)-binding protein, present in the extracellular egg envelope (vitelline envelope (VE)), is a suppressive mediator of sperm-egg interaction. Preincubation with specific antibody greatly increased the efficiency of in vitro fertilization, whereas prior application of exogenous dicalcin substantially inhibited fertilization as well as sperm binding to an egg and in vitro sperm penetration through the VE protein layer. Dicalcin showed binding to protein cores of gp41 and gp37, constituents of VE, in a Ca(2+)-dependent manner and increased in vivo reactivity of VE with a lectin, Ricinus communis agglutinin I, which was accounted for by increased binding ability of gp41 to the lectin and greater exposure of gp41 to an external environment. Our findings strongly suggest that dicalcin regulates the distribution of oligosaccharides within the VE through its binding to the protein core of gp41, probably by modulating configuration of oligosaccharides on gp41 and the three-dimensional structure of VE framework, and thereby plays a pivotal role in sperm-egg interactions during fertilization.
منابع مشابه
Fertilization competence of the egg-coating envelope is regulated by direct interaction of dicalcin and gp41, the Xenopus laevis ZP3
Fertilization begins with species-restricted interaction of sperm and the egg-coating envelope, which includes a three-dimensional meshwork of filaments composed of glycoproteins (called ZP proteins). Growing evidence has unveiled the molecular nature of ZP proteins; however, the structural property conferring fertilization competence to the egg-coating envelope remains unknown. Here, we show t...
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Protein-carbohydrate interaction regulates multiple important processes during fertilization, an essential biological event where individual gametes undergo intercellular recognition to fuse and generate a zygote. In the mammalian female reproductive tract, sperm temporarily adhere to the oviductal epithelium via the complementary interaction between carbohydrate-binding proteins on the sperm m...
متن کاملCorrigendum: Fertilization competence of the egg-coating envelope is regulated by direct interaction of dicalcin and gp41, the Xenopus laevis ZP3
In the Abstract, " The interactive regions between dicalcin and gp41 comprised six and nine amino acid residues within dicalcin and twenty-three within gp41. " now reads: " The interactive regions between dicalcin and gp41 comprised five and nine amino acid residues within dicalcin and twenty-three within gp41. " In the Introduction, " Among them, dcp11 (S-F-S-C-N-Q-K-N-K) and dcp15 (A-A-L-C-K-...
متن کاملGamete Interactions in Xenopus laevis: Identification of Sperm Binding Glycoproteins in the Egg Vitelline Envelope
A quantitative assay was developed to study the interaction of Xenopus laevis sperm and eggs. Using this assay it was found that sperm bound in approximately equal numbers to the surface of both hemispheres of the unfertilized egg, but not to the surface of the fertilized egg. To understand the molecular basis of sperm binding to the egg vitelline envelope (VE), a competition assay was used and...
متن کاملXenopus laevis sperm-egg adhesion is regulated by modifications in the sperm receptor and the egg vitelline envelope.
The biochemical and ultrastructural changes in the envelope of the Xenopus laevis egg that occur during oviposition and fertilization have been thoroughly studied (Hedrick, J. L., and Nishihara, D. M., Methods Cell Biol. 36, 231-247, 1991; Larabell, C. A., and Chandler, D. E., J. Electron Microsc. Tech. 17, 294-318, 1991). However, the biological significance of these changes with respect to ga...
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ورودعنوان ژورنال:
- The Journal of biological chemistry
دوره 285 20 شماره
صفحات -
تاریخ انتشار 2010