JUND

JunD is a transcription factor in humans encoded by the JUND gene. It belongs to the JUN family and is a component of the AP-1 transcription factor complex. JunD forms dimers with FOS family members or other JUN proteins to bind AP-1–responsive DNA elements and regulate gene expression.

JunD contains a basic region leucine zipper (bZIP) domain that mediates DNA binding and dimerization. Its activity is regulated by post-translational modifications and interactions with co-factors, as well as by signaling pathways that respond to growth factors, cytokines, and cellular stress.

Biological roles of JunD are context-dependent. It influences cell proliferation, differentiation, and survival, and participates in stress responses. In cancer research, JunD can act as a proto-oncogene in some settings, while in others it exhibits anti-oncogenic or tumor-suppressive effects.

Genetic and animal studies indicate that perturbations of JunD affect transformation susceptibility, aging, and stress responses, highlighting its complex role in AP-1 signaling and cellular homeostasis.

In cells, JunD interacts within the AP-1 network with c-Jun, JunB, and FOS proteins, and can recruit chromatin modifiers and co-activators to regulate transcription. The JUND gene and JunD protein are subjects of ongoing research in development and disease.