Figure 4: Acetylated Proteins Potentially Involved in the Control of HIF-1α Maturation and Stability. HDACIs may lead to hyperacetylation of one or more proteins involved in the folding process of HIF-1α. Similar to HSP90 inhibition-caused blockage of normal folding and mature processes of HIF-1α, unfolded or misfolded HIF-1α remains interacting with HSP70, which may eventually trigger a ubiquitination-independent degradation process.