Growth arrest and DNA-damage-inducible protein GADD45 alpha (GADD45A)

Growth arrest and DNA-damage-inducible protein GADD45 alpha (GADD45A) is a small, acidic nuclear protein encoded by the GADD45A gene that is rapidly induced by DNA damage, genotoxic stress, and other environmental insults. GADD45A is part of the GADD45 family of stress response proteins, acting as a critical mediator in cellular processes including cell cycle control, growth arrest, DNA repair, apoptosis, and maintenance of genomic stability. Its functions are linked to interactions with proteins such as proliferating cell nuclear antigen (PCNA), p21, Cdc2-cyclinB complex, MTK1/MEKK4 kinase, and histones, and it regulates stress-responsive signaling pathways such as p38 MAPK/JNK via MEKK4. GADD45A functions as a tumor and autoimmune disease suppressor and facilitates active DNA demethylation through interaction with DNA repair enzymes. Its expression serves as a biomarker for cellular DNA damage and stress, commonly used in genotoxicity screening assays. Oligomerization of GADD45A (forming mainly dimers) is essential for its function in nuclear localization and DNA/nucleosome accessibility. Dysregulation of GADD45A is associated with cancer, autoimmune conditions, and impaired genomic stability. As of now, GADD45A is considered a stress response mediator and DNA repair-associated protein rather than a direct therapeutic drug target, though its pathway modulation alters cellular response to chemotherapy and other stressors.

Other names

DDIT1DDIT-1GADD45DNA damage-inducible transcript 1 proteingrowth arrest and DNA damage-inducible protein GADD45 alphaDNA damage-inducible transcript-1growth arrest and DNA-damage-inducible 45 alpha

Drugs that induce DNA damage increase GADD45A expression; functions include promoting cell cycle arrest, facilitating DNA repair, and activating stress-activated MAPK pathways (e.g., p38/JNK)