The N-terminal region of HASPIN regulates phosphorylation of AURKA and meiotic progression in spermatocytes.

Protein phosphorylation is an important post-translational modification that plays a critical regulatory role in meiosis. HASPIN, a kinase highly conserved from yeast to mammals, is required for male fertility. In this study, we found that the intrinsically disordered N-terminal domain of HASPIN is also required for this function. Mice with deletion of N-terminal amino acids (aa) 1-243 of HASPIN exhibited reduced testicular size, sperm count, and fertility. Using immunoprecipitation-mass spectrometry and phosphoproteomics analysis, we found that HASPIN could interact with AURKA and regulate its phosphorylation at T279 via its N-terminus. Taken together, our results suggest that the N-terminus of HASPIN regulates AURKA kinase activity to affect male fertility.