Using ZINC08918027 inhibitor to determine Aurora kinase-chromosomal passenger complex isoforms in mouse oocytes

Abstract

Objective Miscarriages affect 10% of women aged 25–29, and 53% of women over 45. The primary cause of miscarriage is aneuploidy that originated in eggs. The Aurora kinase family has three members that regulate chromosome segregation. Therefore, distinguishing the roles of these isoforms is important to understand aneuploidy etiology. In meiosis, Aurora kinase A (AURKA) localizes to spindle poles, where it binds TPX2. Aurora kinase C (AURKC) localizes on chromosomes, where it replaces AURKB as the primary AURK in the chromosomal passenger complex (CPC) via INCENP binding. Although AURKA compensates for CPC function in oocytes lacking AURKB/C, it is unknown whether AURKA binds INCENP in wild type mouse oocytes. ZINC08918027 (ZC) is an inhibitor that prevents the interaction between AURKB and INCENP in mitotic cells. We hypothesized that ZC would block CPC function of any AURK isoform. Results ZC treatment caused defects in meiotic progression and spindle building. By Western blotting and immunofluorescence, we observed that activated AURKA and AURKC levels in ZC-treated oocytes decreased compared to controls. These results suggest there is a population of AURKA-CPC in mouse oocytes. These data together suggest that INCENP-dependent AURKA and AURKC activities are needed for spindle bipolarity and meiotic progression.

Spatio-temporal requirements of Aurora kinase A in mouse oocytes meiotic spindle building

“…The mammalian genome encodes three members: Aurora kinase A (AURKA), Aurora kinase B (AURKB), and Aurora kinase C (AURKC). AURKA mainly localizes with aMTOCs [12, 13], with a minor chromosomal population [14]. Through mouse knockout studies, we found that although each isoform is important for female fertility and oocyte meiosis, only AURKA is necessary and sufficient for fertility [1, 2].…”