SNAREs in mammalian sperm: possible implications for fertilization.
Soluble N-ethylmalameide-sensitive factor attachment protein receptor (SNARE) proteins are present in mammalian sperm and could be involved in critical membrane fusion events during fertilization, namely the acrosome reaction. Vesicle-associated membrane protein/synaptobrevin, a SNARE on the membrane of a vesicular carrier, and syntaxin 1, a SNARE on the target membrane, as well as the calcium sensor synaptotagmin I, are present in the acrosome of mammalian sperm (human, rhesus monkey, bull, hamster, mouse). Sperm SNAREs are sloughed off during the acrosome reaction, paralleling the release of sperm membrane vesicles and acrosomal contents, and SNARE antibodies inhibit both the acrosome reaction and fertilization, without inhibiting sperm-egg binding. In addition, sperm SNAREs may be responsible, together with other sperm components, for the asynchronous male DNA decondensation that occurs following intracytoplasmic sperm injection, an assisted reproduction technique that bypasses normal sperm-egg surface interactions. The results suggest the participation of sperm SNAREs during membrane fusion events at fertilization in mammals.
Ramalho-Santos
J
J
Division of Reproductive Sciences, Oregon Regional Primate Research Center, Beaverton, Oregon 97006, USA.
Moreno
R D
RD
Sutovsky
P
P
Chan
A W
AW
Hewitson
L
L
Wessel
G M
GM
Simerly
C R
CR
Schatten
G
G
D020101:Acrosome Reaction; D000818:Animals; D015153:Blotting, Western; D002135:Calcium-Binding Proteins; D002417:Cattle; D006224:Cricetinae; D004591:Electrophoresis, Polyacrylamide Gel; D005033:Ethylmaleimide / Q000378:metabolism*; D005306:Fertilization / Q000235:genetics* / Q000502:physiology*; D005307:Fertilization in Vitro; D006801:Humans; D007150:Immunohistochemistry; D008253:Macaca mulatta; D008297:Male; D008561:Membrane Fusion; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D008565:Membrane Proteins / Q000096:biosynthesis; D051379:Mice; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D050683:R-SNARE Proteins; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism*; D050863:Synaptotagmin I; D050857:Synaptotagmins
D002135:Calcium-Binding Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D050683:R-SNARE Proteins; C494310:SYT1 protein, human; D050863:Synaptotagmin I; C494311:Syt1 protein, mouse; D050857:Synaptotagmins; D005033:Ethylmaleimide