spliceostatin-a and 4-5-6-7-tetrabromo-2-azabenzimidazole

SAP155 is an essential component of the spliceosome and its phosphorylation is required for splicing catalysis, but little is known concerning its function and regulation during spermatogenesis in postnatal murine testes. We report that inhibition of dual-specificity tyrosine-phosphorylation regulated kinase (DYRK) IA strongly suppressed the mitogen-stimulated SAP155 phosphorylation and constitutive splicing of IκB pre-mRNA as well as the proliferation of spermatogonial and Sertoli cells in cultures of the 6-day post partum testes and a spermatogonial cell line, but not in a Sertoli cell line. Our findings suggest that the active spliceosome, containing SAP155 phosphorylated by DYRKIA, performs pre-mRNA splicing in spermatogonia during testicular development.

Topics: Animals; Animals, Newborn; Cell Line; Cell Proliferation; Cyclin-Dependent Kinase 2; Dyrk Kinases; Male; Mice; Phosphoproteins; Phosphorylation; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Pyrans; Ribonucleoprotein, U2 Small Nuclear; RNA Precursors; RNA Splicing; RNA Splicing Factors; Sertoli Cells; Spermatogonia; Spiro Compounds; Spliceosomes; Testis; Triazoles