Role of Sperm Surface Arylsulfatase A in Mouse Sperm-Zona Pellucida Binding1

Abstract

We have previously described the zonae pellucidae (ZP) binding ability of a pig sperm surface protein, P68. Our recent results on peptide sequencing of 3 P68 tryptic peptides and molecular cloning of pig testis arylsulfatase A (AS-A) revealed the identity of P68 as AS-A. In this report, we demonstrate the presence of AS-A on the mouse sperm surface and its role in ZP binding. Using anti-AS-A antibody, we have shown by immunoblotting that AS-A was present in a Triton X-100 extract of mouse sperm. The presence of AS-A on the sperm plasma membrane was conclusively demonstrated by indirect immunofluorescence, immunogold electron microscopy, and AS-A's desulfation activity on live mouse sperm. The AS-A remained on the head surface of in vivo capacitated sperm, as revealed by positive immunofluorescent staining of oviductal/uterine sperm. Significantly, the role of mouse sperm surface AS-A on ZP binding was demonstrated by dose-dependent decreases of sperm-ZP binding on sperm pretreatment with anti-AS-A IgG/Fab. Furthermore, Alexa-430 conjugated AS-A bound to mouse ZP of unfertilized eggs but not to fertilized ones, and this level of binding increased and approached saturation with increasing Alexa-430 AS-A concentrations. Moreover, in vivo fertilization was markedly decreased when mouse sperm pretreated with anti-AS-A IgG were artificially inseminated into females. All of these results designated a new function for AS-A in mouse gamete interaction.

Characterization of a novel ZP3-independent sperm-binding ligand that facilitates sperm adhesion to the egg coat

“…As UDP-galactose is able to force the catalytic dissociation of any putative galactosyltransferase from its galactosylated product, this result suggests that no other members of the GalT family function during the binding of GalT I-null sperm to the zona pellucida. However, any of the other sperm components recently implicated in ZP3-independent sperm-egg binding, such as SED1 or arylsulfatase A, could function as the receptor for this novel, ZP3-independent ligand (Ensslin and Shur, 2003;Tantibhedhyangkul et al, 2002;White et al, 2000).…”

Arylsulfatase A deficiency causes seminolipid accumulation and a lysosomal storage disorder in Sertoli cells

“…General protocols were as previously described ( 21 ). Motile sperm were collected from the swim-up fraction, and an equal number of wild-type and Arsa Ϫ / Ϫ sperm were added to medium droplets, each containing 20-30 ovulated eggs retrieved from superovulated wild-type females.…”

Cellular mechanisms regulating sperm–zona pellucida interaction

“…This argument, however, appears to be at odds with the relatively high degree of cross-species conversation recorded among the known sperm-ZP receptors. 112,[126][127][128][129][130] Nonetheless, recent data regarding the role of the sperm protein, zonadhesin, promises to improve our understanding of the mechanisms behind the speciesspecific nature of sperm-ZP binding. 131 In this context, it has been shown that targeted deletion of zonadhesin leads to the production of mouse spermatozoa that bind promiscuously to the ZP of several divergent species.…”