Abstract: Objective To find out which proteins of histone acetylase (HATs) and histone deacetylase (HDACs) interact with Islet-1 during the differentiation of C3H10T1/2 cells transfected with Islet-1 lentiviral vector into cardiomyocyte-like cells, and to confirm the pivotal role of Islet-1 in the network of histone acetylation. Methods Culture and observe C3H10T1/2 cells transfected with Islet-1 lentiviral vector. The position of Islet-1 was detected by Immunofluorescence cytochemistry. The protein extraction time was determined by Western-blot according to expression levels of Islet-1-immunoprecipitation. The Islet-1-binding protein was precipitated by Co-immunoprecipitation-polyacrylamde (Co-IP). The proteins of HATs and HDACs interacting with Islet-1 were verified by Western-blot. Results Cells in induction group showed the appearance of cardiomyocyte-like cells. The location of Islet-1 was in cytoplasm. The protein extraction time in induction group was significant in the third week (0.782±0.015) compared with the first 2 weeks. The expression of Islet-1 in induction group was significantly higher than that in blank control group and C3H10 group (0.819±0.026，0.127±0.006 and 0.126±0.001 respectively, P<0.05）.The proteins interacting with Islet-1 were GCN5、P300/CBP and HDAC4. Conclusions The synergism of Islet-1 and its interacting proteins such as GCN5、P300/CBP and HDAC4 played a specific assisting role in the differentiation of C3H10T1/2 cells into cardiomyocyte-like cells.

Key words: C3H10T1/2 cells, Islet-1, cardiomyocyte-like cells, histone acetylation