Dissemin is shutting down on January 1st, 2025

Published in

Portland Press, Biochemical Society Transactions, 6(42), p. 1740-1743, 2014

DOI: 10.1042/bst20140218

Links

Tools

Export citation

Search in Google Scholar

Moonlighting proteins in sperm–egg interactions

Journal article published in 2014 by François M Petit ORCID, Catherine Serres, Jana Auer
Distributing this paper is prohibited by the publisher
Distributing this paper is prohibited by the publisher

Full text: Unavailable

Red circle
Preprint: archiving forbidden
Orange circle
Postprint: archiving restricted
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

Sperm–egg interaction is a highly species-specific step during the fertilization process. The first steps consist of recognition between proteins on the sperm head and zona pellucida (ZP) glycoproteins, the acellular coat that protects the oocyte. We aimed to determine which sperm head proteins interact with ZP2, ZP3 and ZP4 in humans. Two approaches were combined to identify these proteins: immunoblotting human spermatozoa targeted by antisperm antibodies (ASAs) from infertile men and far-Western blotting of human sperm proteins overlaid by each of the human recombinant ZP (hrZP) proteins. We used a proteomic approach with 2D electrophoretic separation of sperm protein revealed using either ASAs eluted from infertile patients or recombinant human ZP glycoproteins expressed in Chinese-hamster ovary (CHO) cells. Only spots highlighted by both methods were analysed by MALDI–MS/MS for identification. We identified proteins already described in human spermatozoa, but implicated in different metabolic pathways such as glycolytic enzymes [phosphokinase type 3 (PK3), enolase 1 (ENO1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), aldolase A (ALDOA) and triose phosphate isomerase (TPI)], detoxification enzymes [GST Mu (GSTM) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) 4], ion channels [voltage-dependent anion channel 2 (VDAC2)] or structural proteins (outer dense fibre 2). Several proteins were localized on the sperm head by indirect immunofluorescence, and their interaction with ZP proteins was confirmed by co-precipitation experiments. These results confirm the complexity of the sperm–ZP recognition process in humans with the implication of different proteins interacting with the main three ZP glycoproteins. The multiple roles of these proteins suggest that they are multifaceted or moonlighting proteins.