title: Phosphorylation of sperm histone H1 is induced by the egg jelly layer in the sea urchin Strongylocentrotus purpuratus.
abstract: Phosphorylation of histone H1 occurs when spermatozoa of the sea urchin Strongylocentrotus purpuratus are treated with the macromolecular fraction of solubilized egg jelly. Phosphorylation is on serine residues in the N-terminal fragment of H1 bisected with N-bromosuccinimide. Phosphorylation is maximal by 4-8 min and dependent on Ca2+, but independent of Na+ or increased intracellular pH. Phosphorylation of H1 can be dissociated from the induction of the acrosome reaction. Only a fraction of the H1 molecules become phosphorylated upon treatment of sperm with egg jelly. The amount of phosphate per mole of H1 increases from 0.15 moles before jelly treatment to 0.46 moles after maximal phosphorylation. Phosphorylation of H1 occurs in a cAMP-dependent manner as indicated by the ability of the phosphodiesterase inhibitors IBMX and SQ20009 to induce H1 phosphorylation. This phosphorylation reaction can be blocked by digesting the sperm surface with Pronase, or preincubation of sperm in wheat germ agglutinin, showing that a ligand in egg jelly must interact with a sperm surface receptor to activate the kinase phosphorylating H1.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D001974:Bromosuccinimide / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006657:Histones / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000494:pharmacology; D008297:Male; D008970:Molecular Weight; D009865:Oocytes / Q000378:metabolism*; D010766:Phosphorylation; D011402:Pronase / Q000378:metabolism; D012617:Sea Urchins; D012964:Sodium / Q000378:metabolism; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000378:metabolism*; D013997:Time Factors; D014909:Wheat Germ Agglutinins
chemical_list: D006657:Histones; D037102:Lectins; D014909:Wheat Germ Agglutinins; D012964:Sodium; D000242:Cyclic AMP; D011402:Pronase; D001974:Bromosuccinimide; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine