Figure 2.

ΔFOSB structure and function are dynamic. (A) Under naive conditions, ΔFOSB predominantly forms high-affinity heterodimers with JUND. Upon accumulation in response to chronic stimuli, ΔFOSB forms homodimers or larger oligomers that may have different DNA binding affinity or target sites. (B) ΔFOSB and JUND heterodimerize via a leucine zipper motif, allowing DNA binding and bringing cysteines 172 and 285 into close proximity. Upon oxidative stress, a disulfide bond forms between the two cysteines, causing a kink in the ΔFOSB helical structure and preventing the complex from binding DNA.