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DOE OSTI · 23137326

Decrease in the cytosolic NADP+-dependent isocitrate dehydrogenase activity through porcine sperm capacitation

Katoh, Yuki·Tamba, Michiko·Matsuda, Manabu·Kikuchi, Kazuhiro·Okamura, Naomichi
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Abstract

Highlights: • IDPc is phosphorylated at tyrosine residues during porcine sperm capacitation. • The tyrosine phosphorylated IDPc showed a significantly lowered enzymatic activity. • IDPc is mainly localized to the principal piece of the porcine sperm flagellum. • The decrease in IDPc activity is involved in the increased levels of ROS. • The decrease in IDPc activity induced the induction of the hyperactivated motility. In order to understand the molecular mechanisms involved in the sperm capacitation, we have identified the proteins tyrosine-phosphorylated during the capacitation especially in conjunction with the regulation of the levels of reactive oxygen species (ROS) in sperm. In the present study, the effects of the tyrosine phosphorylation of cytosolic NADP{sup +}-dependent isocitrate dehydrogenase (IDPc) on its catalytic activity and on the levels of ROS in sperm have been studied. The tyrosine phosphorylated IDPc showed a significantly lowered enzymatic activity. The immunocytochemical analyses using the highly specific antisera against IDPc revealed that IDPc was mainly localized to the principal piece of the porcine sperm flagellum. As IDPc is one of the major NADPH regenerating enzymes in porcine sperm, it is strongly suggested that the decrease in IDPc activity is involved in the increased levels of ROS, which results in the induction of hyperactivated flagellar movement and capacitation.

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60 APPLIED LIFE SCIENCESOXIDOREDUCTASESOXYGENPHOSPHORYLATIONSPERMATOZOATYROSINE

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Katoh, Yuki, Tamba, Michiko, Matsuda, Manabu, Kikuchi, Kazuhiro, Okamura, Naomichi. 2018-02-15. Decrease in the cytosolic NADP+-dependent isocitrate dehydrogenase activity through porcine sperm capacitation. https://doi.org/10.1016/j.bbrc.2018.02.087

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