Takashi Ikeda, Takafusa Hikichi, Hisashi Miura, Hirofumi Shibata, Kanae Mitsunaga, Yosuke Yamada, Knut Woltjen, Kei Miyamoto, Ichiro Hiratani, Yasuhiro Yamada, Akitsu Hotta, Takuya Yamamoto, Keisuke Okita, Shinji Masui (2018) Srf destabilizes cellular identity by suppressing cell-type-specific gene expression programs., Nature communications, Volume 9, Number 1, pp. 1387
Published in 2018 Apr 11 (Electronic publication in April 11, 2018, midnight )
(Abstract) Multicellular organisms consist of multiple cell types. The identity of these cells is primarily maintained by cell-type-specific gene expression programs; however, mechanisms that suppress these programs are poorly defined. Here we show that serum response factor (Srf), a transcription factor that is activated by various extracellular stimuli, can repress cell-type-specific genes and promote cellular reprogramming to pluripotency. Manipulations that decrease beta-actin monomer quantity result in the nuclear accumulation of Mkl1 and the activation of Srf, which downregulate cell-type-specific genes and alter the epigenetics of regulatory regions and chromatin organization. Mice overexpressing Srf exhibit various pathologies including an ulcerative colitis-like symptom and a metaplasia-like phenotype in the pancreas. Our results demonstrate an unexpected function of Srf via a mechanism by which extracellular stimuli actively destabilize cell identity and suggest Srf involvement in a wide range of diseases.(MeSH Terms)