Glycosidases Interact Selectively With Mannose-6-Phosphate Receptors of Bull Spermatozoa

AGUILERA AC; BOSCHÍN V; CARVELLI L; CAVICCHIA JC; SOSA MA

JOURNAL OF CELLULAR BIOCHEMISTRY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2016

0730-2312

Glycosidases may play a role in sperm maturation during epididymal transit. In this work we describe the interaction of these enzymes with bull spermatozoa. We found that β-galactosidase associated to spermatozoa can be released under low ionic strength conditions, whereas the interaction of N-acetyl-β-D-glucosaminidase and β-glucuronidase with spermatozoa appeared to be stronger. On the other hand, α-mannosidase and α-fucosidase cannot be removed from the gametes. In addition, part of N-acetyl-β-D-glucosaminidase, β-galactosidase and β-glucuronidase can also be released by mannose-6-phosphate. Taking into account these data, we explored the presence of cation-independent- and cation-dependent-mannose-6-phosphate receptors in the spermatozoa and found that cation-independent mannose-6-phosphate receptor is highly expressed in bull spermatozoa and cation-dependent- mannose-6-phosphate receptor is expressed at a lesser extent. In addition, by immunofluorescence, we observed that cation-independent- mannose-6-phosphate receptor is mostly located at the acrosomal zone, whereas cation-dependent-mannose-6-phosphate receptor presents a different distribution pattern on spermatozoa during the epididymal transit. N-acetyl-β-D-glucosaminidase and β-glucuronidase isolated from epididymal fluid interacted mostly with cation-independent- mannose-6-phosphate receptor, while β-galactosidase was recognized by both receptors. We concluded that glycosidases might play different roles in bull spermatozoa and that mannos-6-phosphate receptors may act as recruiters of some enzymes.