Reprobing showed that p53 was also recovered by Ub-agarose beads, but only in cells overexpressing ING1b. This indicates the development of Ub-ING1b-p53-complexes, given that p53 was not witnessed in the absence of ING1b-overexpression. Provided that the ING2-PHD was essential for activating p53, we following examined if an ING1-carboxyl-terminal deletion stabilized unmodified and/or mono220551-92-8 ubiquitinated p53. Wt-, but not the deleted sort of ING1 stabilized both endogenous and ectopically expressed p53 to a degree similar to the influence of the proteasome-inhibitor MG132. Considering that ING1 promoted accumulation of ubiquitinated forms of p53, we examined the ING1 protein sequence for motifs identified to be involved in Ub-binding. We discovered a UBD adjacent to the ING1 PHD, which was previously explained as a PBR, needed and sufficient for the binding of PIs. Nuclear magnetic resonance evaluation has shown that UBD binding can block entry to the K48 residue of Ub, therefore blocking polyubiquitination that targets GFT505 proteins to the proteasome. Provided that numerous proteins influencing proteasomal pathways include UBDs, this recommended a function for ING1 in regulating p53 stability by means of this pathway.