The survival effect of mitochondrial Higd-1a is associated with suppression of cytochrome C release and prevention of caspase activation

► Here we have shown that Higd-1a is induced by hypoxia in a HIF-dependent manner. ► Higd-1a enhances survival by suppressing cytochrome C release and caspase activation. ► The N-terminal 26 a.a region of Higd-1a is indispensable for this survival effect. ► Higd-2a also promoted cell survival under hypoxic conditions. ► This is the first report concerning the mechanisms of action and induction of Higd.