DNA‐binding sperm proteins with oligo‐arginine clusters function as potent activators for egg CK‐II

[摘要]

The stimulatory effect of DNA-binding sperm proteins (histone and protamine) on the phosphorylation of p98 (ERp99/GRp94, one of the Hsp-90 family of proteins) by egg casein kinase II (CK-II) was investigated in vitro. It was found that (i) phosphorylation of p98 by egg CK-II in vitro is greatly stimulated by poly-Arg, but not by poly-Lys; and (ii) similar stimulation is observed with sperm histones H2B₂ and H2B₃ (sea urchin) and fish protamines, such as salmine A₁ (salmon) and protamine 3a (rainbow trout). These findings suggest that these DNA-binding sperm proteins function as potent activators for CK-II in fertilized eggs. All of these DNA-binding sperm proteins contain at least an oligo-Arg cluster as a common feature, which can interact with an acidic amino acid cluster of the regulatory β-subunit CK-II.

[学科分类] 生物化学/生物物理

[关键词] Casein kinase II;DNA-binding sperm protein;Protamine;Activation of CK-II;Heat shock protein-90;Sea urchin;CK-II;casein kinase II;DTT;dithiothreitol;ERp99;99 kDa endoplasmic reticulum protein;GRp94;94 kDa glucose regulated protein;HPLC;high performance liquid chromatography;Hsp-90;heat shock protein-90;p98;98 kDa polypeptide;Arg;l-arginine;Lys;l-lysine;PMSF;phenylmethylsulfonyl fluoride;SDS-PAGE;sodium dodecyl-sulfate polyacrylamide gel electrophoresis