Transcription factor AP-2 alpha, N-terminal (IPR008121)

Short name: TF_AP2_alpha_N

Overlapping homologous superfamilies


Domain relationships



Activator protein-2 (AP-2) transcription factors constitute a family of closely related and evolutionarily conserved proteins that bind to the DNA consensus sequence GCCNNNGGC and stimulate target gene transcription [PMID: 2010091, PMID: 1998122]. Four different isoforms of AP-2 have been identified in mammals, termed AP-2 alpha, beta, gamma and delta. Each family member shares a common structure, possessing a proline/glutamine-rich domain in the N-terminal region, which is responsible for transcriptional activation [PMID: 2010091], and a helix-span-helix domain in the C-terminal region, which mediates dimerisation and site-specific DNA binding [PMID: 1998122].

The AP-2 family have been shown to be critical regulators of gene expression during embryogenesis. They regulate the development of facial prominence and limb buds, and are essential for cranial closure and development of the lens [PMID: 11137286]; they have also been implicated in tumourigenesis. AP-2 protein expression levels have been found to affect cell transformation, tumour growth and metastasis, and may predict survival in some types of cancer [PMID: 9632718, PMID: 10864206]

AP-2 alpha was initially isolated from human HeLa cells [PMID: 3040262]. The protein was shown to bind to enhancer regions of the SV40 and human metallothionein IIA promoters, and to stimulate RNA synthesis [PMID: 3040262]. AP-2 alpha gene knockout in mice causes neural-tube defects during embryogenesis, leading to craniofacial abnormalities and anencephaly [PMID: 8622766]. In humans, deletion of chromosome 6 region 6p24-p25, which includes the AP-2 alpha gene, is associated with microphthalmia, corneal clouding and a number of other dysmorphic features, including hypertelorism, micrognathia, dysplastic ears, thin limbs, and congenital cardiac defects.

This entry represents the N-terminal region of these proteins, including the transcriptional activation domain.

GO terms

Biological Process

GO:0006355 regulation of transcription, DNA-templated

Molecular Function

GO:0003700 DNA-binding transcription factor activity

Cellular Component

GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.