GA binding protein transcription factor alpha subunit(GABPA) Homo sapiens. This gene encodes one of three GA-binding protein transcription factor subunits which functions as a DNA-binding subunit. Since this subunit shares identity with a subunit encoding the nuclear respiratory factor 2 gene, it is likely involved in activation of cytochrome oxidase expression and nuclear control of mitochondrial function. This subunit also shares identity with a subunit constituting the transcription factor E4TF1, responsible for expression of the adenovirus E4 gene. Because of its chromosomal localization and ability to form heterodimers with other polypeptides, this gene may play a role in the Down Syndrome phenotype. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Oct 2010],