Phosphomannosyl receptors on the surface of spermatozoa from the cauda epididymis of the rat Article

BARBIERI, AM, SOSA, MA, GRIMALT, P et al. (1995). Phosphomannosyl receptors on the surface of spermatozoa from the cauda epididymis of the rat . 18(3), 113-119. 10.1111/j.1365-2605.1995.tb00396.x

cited authors

  • BARBIERI, AM; SOSA, MA; GRIMALT, P; MAYORGA, LS; BERTINI, F

authors

abstract

  • This study demonstrates that β‐glucuronidase from rat preputial glands binds with high affinity to spermatozoa from the cauda epididymis. The binding was calcium‐independent and was inhibited by mannose‐6‐phosphate, but not by other phosphorylated or non‐phosphorylated sugars. Binding was also inhibited by α‐mannosidase from Dictyostelium discoideum, an enzyme known to have mannose‐6‐phosphate as the ligand. From solubilized sperm membranes, a protein of >200 kDa and one of 45 kDa, were adsorbed to a column of D. discoideum enzyme and to a phosphomannan column respectively, and eluted with mannose‐6‐phosphate. According to histochemical observations at the light and the electron microscopic level, gold particles coated with the enzyme became bound to the external surface of the plasmalemma in the acrosomal region of caudal spermatozoa. Similar labelling was observed using gold particles coated with antibodies against the rat 300 kDa phosphomannosyl receptor. The existence of phosphomannosyl receptors on the sperm plasma membrane, and our previous demonstration of the presence of affinity sites for epididymal β‐galactosidase on these gametes which is inhibited by phosphofructosyl derivatives, suggest strongly that maturing spermatozoa could be a target for glycosidases secreted into the lumen of the cauda epididymis, which then become bound to these cells via different ligand‐receptor systems. Copyright © 1995, Wiley Blackwell. All rights reserved

publication date

  • January 1, 1995

Digital Object Identifier (DOI)

start page

  • 113

end page

  • 119

volume

  • 18

issue

  • 3