PKA activation in concert with ARIS and asterosap induces the acrosome reaction in starfish

Zygote. 2006 Nov;14(4):329-40. doi: 10.1017/S0967199406003881.

Abstract

The acrosome reaction (AR) is a fundamental event for fertilization, which is induced in concert with acrosome reaction-inducing substance (ARIS) and asterosap, both of which are components of starfish egg jelly (EJ). During the AR, a spermatozoon undergoes a series of physiological changes, such as in intracellular cGMP concentration ([cGMP]i), pHi and intracellular Ca2+ concentration ([Ca2+]i). Affinity purification of cGMP-binding protein resulted in the isolation of a regulatory subunit of the cAMP-dependent protein kinase A (PKA), suggesting the involvement of a cAMP-dependent pathway in the AR. By using a cAMP enzyme immunoassay, [cAMP]i was found to increase in starfish spermatozoa when stimulated with ARIS and asterosap. ARIS could also increase the [cAMP]i in the presence of high pH seawater. Pretreatment of spermatozoa with two specific and cell-permeable PKA inhibitors, H89 and KT5720, prevented the induction of the AR in a concentration-dependent manner. These results suggest that PKA activity participates in the induction of the AR with ARIS and asterosap. To investigate this, we have cloned a gene that encodes a regulatory subunit of PKA that had been identified in starfish spermatozoa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrosome Reaction / physiology*
  • Amino Acid Sequence
  • Animals
  • Asterias / genetics
  • Asterias / physiology*
  • Base Sequence
  • Cloning, Molecular
  • Cyclic AMP / metabolism
  • Cyclic AMP-Dependent Protein Kinases / chemistry
  • Cyclic AMP-Dependent Protein Kinases / genetics
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Cyclic GMP / metabolism
  • DNA, Complementary / genetics
  • Enzyme Activation
  • Female
  • Fertilization / physiology
  • Glycoproteins / physiology*
  • Hydrogen-Ion Concentration
  • Intercellular Signaling Peptides and Proteins
  • Male
  • Molecular Sequence Data
  • Phylogeny
  • Protein Subunits
  • Seawater
  • Sequence Homology, Amino Acid

Substances

  • ARIS protein, Asterias amurensis
  • DNA, Complementary
  • Glycoproteins
  • Intercellular Signaling Peptides and Proteins
  • Protein Subunits
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • Cyclic GMP