Identification and cellular location of glutamine synthetase in human sperm.
Glutamine synthetase (GS) catalyzes the de novo synthesis of glutamine, an amino acid that has been shown to influence sperm motility in mammals. To date, no information is available about GS content in human sperm. In this study, we have characterized the presence and cellular location of GS in fresh human normozoospermic samples. We have detected a single band corresponding to GS by Western blot. Confocal analysis has revealed GS immunoreactivity in the post-acrosomal head region. Moreover, double-labeling experiments with either F-actin or calicin have demonstrated GS confinement in the post-acrosomal region of the perinuclear theca. These data have been validated by a post-embedding ultra-structural study. The presence of GS in the post-acrosomal region of the perinuclear theca suggests that human sperm can carry out in glutamine synthesis.
Departamento de Biotecnología, Universidad de Alicante, Ctra. San Vicente-Alicante S/N, 03080 Alicante, Spain.
Maria Manuela
MM
Francou
José R
JR
Hombrebueno
Joaquín
J
De Juan
D000818:Animals; D015153:Blotting, Western; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D021381:Protein Transport; D013094:Spermatozoa / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D014020:Tissue Extracts
D014020:Tissue Extracts; D005974:Glutamate-Ammonia Ligase