STUB1 and Hyperglycemia: Although the CHIP mutants (K30A and H260Q) can bind with p53, neither of them can induce ubiquitination, suggesting that both domains of CHIP are involved in ubiquitination and proteasomal degradation of hyperglycemia-activated p53, and possibly the chaperone system is involved in assisting ubiquitination of p53 as K30A domain mutant lose its potential to interact with chaperones (HSP70/90) (Fig. 4D-E).