TY - JOUR
T1 - Glycogen synthase kinase 3 regulates acrosomal exocytosis in mouse spermatozoa via dynamin phosphorylation
AU - Reid, Andrew T.
AU - Anderson, Amanda L.
AU - Roman, Shaun D.
AU - McLaughlin, Eileen A.
AU - McCluskey, Adam
AU - Robinson, Phillip J.
AU - Aitken, R. John
AU - Nixon, Brett
N1 - © FASEB.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - The dynamin family of GTPases has been implicated as novel regulators of the acrosome reaction, a unique exocytotic event that is essential for fertilization. Dynamin activity during the acrosome reaction is accompanied by phosphorylation of key serine residues. We now tested the hypothesis that glycogen synthase kinase 3 (GSK3) is the protein kinase responsible for dynamin phosphorylation at these phosphosites in mouse spermatozoa. Pharmacologic inhibition of GSK3 in mature mouse spermatozoa (CHIR99021: IC50 = 6.7 nM) led to a significant reduction in dynamin phosphorylation (10.3% vs. 27.3%; P< 0.001), acrosomal exocytosis (9.7% vs. 25.7%; P<0.01), and in vitro fertilization (53% vs. 100%;P<0.01). GSK3 was shown to be present in developing germ cells where it colocalized with dynamin in the peri-acrosomal domain. However, additional GSK3 was acquired by maturing mouse spermatozoa within the male reproductive tract, via a novel mechanism involving direct interaction of sperm heads with extracellular structures known as epididymal dense bodies. These data reveal a novel mode for the cellular acquisition of a protein kinase and identify a key role for GSK3 in the regulation of sperm maturation and acrosomal exocytosis.
AB - The dynamin family of GTPases has been implicated as novel regulators of the acrosome reaction, a unique exocytotic event that is essential for fertilization. Dynamin activity during the acrosome reaction is accompanied by phosphorylation of key serine residues. We now tested the hypothesis that glycogen synthase kinase 3 (GSK3) is the protein kinase responsible for dynamin phosphorylation at these phosphosites in mouse spermatozoa. Pharmacologic inhibition of GSK3 in mature mouse spermatozoa (CHIR99021: IC50 = 6.7 nM) led to a significant reduction in dynamin phosphorylation (10.3% vs. 27.3%; P< 0.001), acrosomal exocytosis (9.7% vs. 25.7%; P<0.01), and in vitro fertilization (53% vs. 100%;P<0.01). GSK3 was shown to be present in developing germ cells where it colocalized with dynamin in the peri-acrosomal domain. However, additional GSK3 was acquired by maturing mouse spermatozoa within the male reproductive tract, via a novel mechanism involving direct interaction of sperm heads with extracellular structures known as epididymal dense bodies. These data reveal a novel mode for the cellular acquisition of a protein kinase and identify a key role for GSK3 in the regulation of sperm maturation and acrosomal exocytosis.
KW - Acrosome reaction
KW - Epididymal dense bodies
KW - Sperm maturation
KW - Phosphorylation
KW - Cyclin-Dependent Kinase 5/metabolism
KW - Sperm Maturation/drug effects
KW - Male
KW - Spermatozoa/drug effects
KW - Progesterone/pharmacology
KW - Glycogen Synthase Kinase 3/antagonists & inhibitors
KW - Enzyme Inhibitors/pharmacology
KW - Microscopy, Immunoelectron
KW - Sperm Head/metabolism
KW - Animals
KW - Fertilization in Vitro
KW - Epididymis/metabolism
KW - Exocytosis/physiology
KW - Female
KW - Mice
KW - Dynamin I/chemistry
KW - Acrosome Reaction/drug effects
UR - http://www.scopus.com/inward/record.url?scp=84940434893&partnerID=8YFLogxK
UR - http://www.mendeley.com/research/glycogen-synthase-kinase-3-regulates-acrosomal-exocytosis-mouse-spermatozoa-via-dynamin-phosphorylat
U2 - 10.1096/fj.14-265553
DO - 10.1096/fj.14-265553
M3 - Article
C2 - 25808536
AN - SCOPUS:84940434893
SN - 0892-6638
VL - 29
SP - 2872
EP - 2882
JO - FASEB Journal
JF - FASEB Journal
IS - 7
ER -