Microspherule protein 2 associates with ASK1 and acts as a negative regulator of stress-induced ASK1 activation

► MCRS2 interacts with ASK1 directly. ► ASK1 sequesters MCRS2 in the cytoplasm. ► Overexpression of MCRS2 inhibits H2O2-induced ASK1 phosphorylation. ► Knockdown of MCRS2 accelerates the activation of ASK1 signal pathway. ► H2O2 treatment results in the degradation of MCRS2.