ATF2

ATF2
Name	Activating transcription factor 2
Other names	ATF-2, CRE-BP1, CREB2
Uniprot	P15336
Organism	Human
Location	Nucleus

ATF2 Activating transcription factor 2 is a human transcription factor involved in stress-responsive gene expression, DNA repair, and developmental programs. First characterized in studies of cAMP-responsive element binding, it has been studied across cell biology, oncology, and neuroscience research. ATF2 functions as a dimerizing bZIP protein that integrates signals from MAP kinases and other kinases to regulate transcriptional networks implicated in inflammation, apoptosis, and tumorigenesis.

Introduction

ATF2 was identified through biochemical studies that also characterized factors such as CREB and Jun family proteins and was rapidly connected to signaling cascades illuminated by work on Ras, MEK1, and ERK1/2. Early genetic and biochemical mapping involved laboratories associated with Cold Spring Harbor Laboratory, MIT, and the National Institutes of Health. ATF2 research intersects with investigations into p53, NF-κB, and STAT3 pathways and has implications for cellular responses described in models of ischemia-reperfusion injury, UV radiation, and chemotherapeutic stress.

Structure and Isoforms

ATF2 is a basic leucine zipper (bZIP) protein containing an N-terminal transactivation domain and a C-terminal bZIP DNA-binding and dimerization domain. Structural features were resolved by studies using crystallography and NMR in laboratories such as European Molecular Biology Laboratory and Max Planck Institute, revealing conserved residues mediating interaction with CRE elements characterized in work on c-fos and c-jun. Multiple isoforms arise from alternative splicing and alternative translation initiation; these isoforms vary in transactivation potential and nuclear localization, analogous to isoform diversity described for p63 and p73. Comparative genomics places ATF2 in conserved gene families across species studied by groups at Scripps Research Institute and University of Cambridge.

Function and Mechanism of Action

ATF2 binds DNA at cAMP-responsive elements (CRE) and related motifs to regulate transcription of target genes including those characterized in studies of BCL2, MMP9, and VEGF. As a dimer it associates with members of the AP-1 complex such as c-Jun and with heterodimers involving CREB1; these interactions modulate promoters analyzed in research on cyclin D1 and p21 (CDKN1A). Activation is tightly coupled to phosphorylation by kinases identified in signaling cascades, notably JNK, p38 MAPK, and ATM, coordinating responses to stimuli like UV radiation and double-strand breaks. Functional assays in systems from laboratories at Harvard Medical School and Stanford University demonstrate roles in chromatin remodeling and recruitment of co-activators described in literature on CBP and p300.

Regulation and Post-translational Modifications

ATF2 activity is regulated by multisite phosphorylation, acetylation, and ubiquitination. Phosphorylation at conserved threonine residues by JNK and p38 MAPK enhances transcriptional activation, paralleling modifications characterized for Elk-1 and CREB. DNA damage-dependent phosphorylation by ATM links ATF2 to the DNA damage response studied alongside BRCA1 and CHK2. Acetylation by CBP/p300 and ubiquitin-mediated turnover involving E3 ligases investigated in work from EMBL affect stability and promoter residence time. Regulatory modulation also involves interactions with proteins such as HDAC1 and components of chromatin remodelers studied in the context of SWI/SNF complexes.

Role in Disease and Clinical Significance

Aberrant ATF2 activity has been implicated in cancers including studies of melanoma, breast cancer, and lung carcinoma, where it can function as oncogene or tumor suppressor in a context-dependent manner. Mutational analyses and expression profiling in cohorts from institutions like MD Anderson Cancer Center and Dana-Farber Cancer Institute link ATF2 dysregulation to prognosis and therapy resistance, with connections to pathways regulated by BRAF, EGFR, and PI3K. In neurobiology, ATF2 participates in neuronal survival programs investigated in models involving Parkinson's disease and Alzheimer's disease. Genetic studies and clinical correlative work incorporate data from consortia such as The Cancer Genome Atlas.

Interactions and Signaling Pathways

ATF2 engages a network of protein–protein interactions with transcription factors and signaling mediators including c-Jun, CREB1, CBP, p300, JNK1, p38α, ATM, and Chk2. These interactions place ATF2 at hubs connecting MAP kinase signaling, genotoxic stress responses, and chromatin regulation described in pathway maps curated by groups like KEGG and Reactome. Cross-talk with pathways regulated by NF-κB, STAT3, and β-catenin has been reported in mechanistic studies from laboratories at University of California, San Francisco and Yale University.

Experimental Models and Research Applications

ATF2 function has been dissected using knockout and knock-in mouse models generated at facilities such as Jackson Laboratory and transgenic lines used in developmental studies at European Molecular Biology Laboratory. Cellular models include CRISPR/Cas9-edited lines, RNAi knockdown in cultures employed in work from Cold Spring Harbor Laboratory, and inducible expression systems utilized in pharmaceutical research at Genentech and Novartis. ATF2 reporters, ChIP-seq, and phospho-proteomics have been applied in studies of transcriptional networks alongside methods developed at Broad Institute and Wellcome Sanger Institute. These models support drug discovery efforts targeting kinases upstream of ATF2 and aim to translate findings into clinical trials coordinated by centers like NIH Clinical Center.

Category:Transcription factors