ATF3 is best treated as a stress-inducible nuclear bZIP transcription factor, not as a generic stress pathway component. The falcon deep-research synthesis describes human ATF3 as a nuclear bZIP factor that binds CRE-like motifs and uses partner-dependent dimerization to remodel transcriptional programs [file:human/ATF3/ATF3-deep-research-falcon.md "Human ATF3 (UniProt P18847) is best annotated as a stress-inducible, nuclear bZIP transcription factor"].
The strongest primary evidence supports full-length ATF3 as a transcriptional repressor at ATF-site promoters and as a context-dependent regulator whose output changes with isoform and dimerization state. Chen et al. report that ATF3 represses ATF-site promoters, while ATF3 delta Zip lacks the leucine zipper, does not bind DNA, and can stimulate transcription PMID:7515060. Hashimoto et al. show stress-induced ATF3DeltaZip2 localizes in nuclei, cannot bind the ATF/CRE motif, and counteracts repression by full-length ATF3 PMID:12034827.
The CHOP/GADD153 interaction is real but should be represented specifically. Chen et al. found that CHOP/GADD153 forms a heterodimer with ATF3, but the heterodimer does not bind ATF/CRE DNA and does not repress transcription, unlike the ATF3 homodimer PMID:8622660.
Positive transcriptional regulation is valid only in context. Evidence includes LRF-1/ATF3 with Jun proteins activating a CRE-containing promoter PMID:1406655, ATF3 stimulating EphA1 promoter activity PMID:18308734, and ATF3-dependent DR5 induction during ER-stress/TRAIL sensitization PMID:24939851.
Generic protein binding rows are over-annotated for this review. ATF3 clearly dimerizes with bZIP partners, and partner choice affects DNA specificity PMID:28186491, but broad interaction-screen annotations should not be used as core functional statements when specific homodimerization, heterodimerization, and transcription-factor complex annotations are available.
Two cited rows appear misattributed. PMID:16300731 is an ATF5 paper, not an ATF3 paper PMID:16300731. PMID:14685163 is a CHOP/GADD153 ER-stress review without direct ATF3 evidence PMID:14685163.