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Phosphopeptide Analysis of Rodent Epididymal Spermatozoa
09:30

Phosphopeptide Analysis of Rodent Epididymal Spermatozoa

Published on: December 30, 2014

A cyclic adenosine 3',5'-monophosphate-dependent protein kinase C activation is involved in the hyperactivation of

Hiroshi Harayama1, Masashi Miyake

  • 1The Graduate School of Science and Technology, Kobe University, Kobe, Japan. harayama@kobe-u.ac.jp

Molecular Reproduction and Development
|June 17, 2006
PubMed

Insights

Cyclic AMP-dependent protein kinase A (PKA) signaling activates calcium-sensitive protein kinase Cs (PKCs) in boar sperm. This activation leads to hyperactivation of flagellar movement, crucial for sperm fertilizing ability.

Area of Science:

  • Reproductive Biology
  • Sperm Physiology
  • Cell Signaling

Background:

  • Intracellular cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) signaling are vital for mammalian sperm function.
  • Serine/threonine protein kinases activated by cAMP-PKA signaling are implicated in sperm fertilizing ability.

Purpose of the Study:

  • To investigate the biological function of serine/threonine protein kinases activated by cAMP-PKA signaling in boar spermatozoa.
  • To elucidate the role of these kinases in sperm hyperactivation and fertilizing capacity.

Main Methods:

  • Boar spermatozoa were incubated with a cell-permeable cAMP analog (cBiMPS).
  • Protein kinase Cs (PKCs) activation was analyzed using Western blotting and indirect immunofluorescence.
  • Flagellar movement, including hyperactivation, was assessed.
  • Specific PKC inhibitors and calcium-deficient media were used to determine the role of PKCs and extracellular calcium.

Main Results:

  • Incubation with cBiMPS gradually activated PKCs in the sperm connecting piece via PKA-mediated phosphorylation.
  • Activated PKCs were associated with the onset of hyperactivated flagellar movement.
  • cBiMPS-induced hyperactivation and PKC activation were suppressed by specific PKC inhibitors.
  • Extracellular calcium was required for cBiMPS-induced hyperactivation and PKC activation.

Conclusions:

  • cAMP-PKA signaling activates calcium-sensitive PKCs in boar spermatozoa.
  • Activated PKCs are essential for inducing hyperactivated flagellar movement.
  • cAMP plays a regulatory role in PKC activity, contributing to the expression of sperm fertilizing ability.

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