This gene encodes a mitochondrial integral membrane protein that plays a role in mitochondrial protein homeostasis. The protein contains a P-loop motif and a five-domain structure that is conserved in fly, yeast, and bacteria. It functions to mediate the degradation of nuclear-encoded complex IV subunits. Two conserved estrogen receptor binding sites are located within 2.5 kb of this gene. Polymorphisms in this gene have been associated with bipolar disorder. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Apr 2016].