AP-2γ (Activation protein 2γ, also ERF-1) is a 50 - 55 kDa member of the AP-2 transcription factor family. It is essential for kidney development and placentation of the embryo. In the nucleus, it forms homodimers and heterodimers with other AP-2 family members. Elevated AP-2 family members are highly suggestive of neoplasia. Human AP-2γ is 450 amino acids in length. It contains a repressor SUMOylation site at Lys10, a Gln/Pro-rich transactivation domain (aa 30 - 119) and a helix-span-helix dimerization region (aa 293 - 424). One potential splice form exists that shows a four aa substitution for the N-terminal 16 aa, followed by a premature truncation after Gly130. Over aa 128 - 223, human AP-2γ shares 91% and 82% aa identity with porcine and mouse AP-2γ, respectively.