Synchronous behaviors of CBP and acetylations of lysine 18 and lysine 23 on histone H3 during porcine oocyte first meiotic division

Abstract

As a transcriptional coactivator and acetyltransferase, CREB-binding protein (CBP) is widely characterized due to its functions in cell proliferation and development. However, the activities of CBP in oocyte meiosis are not completely clear. Here we showed that the localization and expression of CBP changed regularly with the progression of porcine oocyte meiosis. The emergence of CBP in chromosomal domains is temporally coincident with the establishments of acetylated lysine 18 (AcH3/K18), lysine 23 (AcH3/K23) and dimethylated arginine 17 (dime-H3/R17) of histone H3 at meiotic stages from germinal vesicle breakdown (GVBD) to metaphase I (MI). Both CBP expression and these three histone modifications persisted to telophase I (TI). When trichostatin A (TSA) was used to enhance histone acetylations in porcine oocytes, we found that hyperacetylations of H3K18 and H3K23 occurred at meiotic stage from GVBD to TI, together with advanced and enhanced expression of CBP in the nucleus. In addition, disturbance of CBP activity by treatment with 2-Naphthol-AS-Ephosphate (KG-501, a drug targeting the KIX domain of CBP that disrupts the formation of CBP functional complex) led to synchronous decreases of CBP expression, AcH3/K18 and AcH3/K23 in chromosomal domains during oocyte meiosis. Therefore, these results indicate that the synchronous changes of CBP expression, AcH3/K18 and AcH3/K23 occur during porcine oocyte meiosis.