Uses
Activating transcription factor 3 (ATF3) is encoded by the gene mapped to human chromosome 1q. It belongs to the ATF/cAMP response element binding (CREB) family of transcription factors. The encoded protein contains a basic region involved in specific DNA binding, and a leucine zipper (bZIP) motif responsible for forming homodimers or heterodimers with other bZIP-containing proteins. ATF3 protein is expressed at low levels in normal and quiescent cells, but its expression is triggered on exposure to extracellular signals such as, growth factors, cytokines and some genotoxic stress agents.
Activating transcription factor 3 is a member of the mammalian activation transcription factor/cAMP responsive element-binding (CREB) protein family of transcription factors. Multiple transcript variants encoding two different isoforms have been found for this gene. The longer isoform represses rather than activates transcription from promoters with ATF binding elements. The shorter isoform (deltaZip2) lacks the leucine zipper protein-dimerization motif and does not bind to DNA, and it stimulates transcription presumably by sequestering inhibitory co-factors away from the promoter. It is possible that alternative splicing of the ATF3 gene may be physiologically important in the regulation of target genes. (provided by RefSeq)
Biological Activity
Activating transcription factor 3 (ATF3) plays a vital role as a novel neuronal marker of nerve injury in the nervous system. ATF3 negatively regulates toll-like receptors (TLR)-stimulated inflammatory response. The encoded protein possibly plays an essential role in homeostasis, wound healing, cell adhesion, cancer cell invasion, apoptosis and signaling pathways. Over-expression of this protein stops cell cycle progression. Increased expression of ATF3 on exposure to stress signals or DNA damage, is regulated by various signaling pathway including, p53-dependent and -independent pathways, and may also involve mitogen-activated protein (MAP) kinase signaling pathways.
ATF3 plays bifurcated roles in cancer development by stimulating apoptosis in the untransformed MCF10A (a breast cancer progression cell line) mammary epithelial cells and also conserve aggressive MCF10CA1a cells and promotes its cell motility.
