Class I histone deacetylases (HDACs) are known to remove acetyl groups from 
histone tails. This liberates positive charges on the histone tail and allows 
for tighter winding of DNA, preventing transcription factor binding and gene 
activation. Although the functions of HDAC proteins are becoming apparent both 
biochemically and clinically, how this class of proteins is regulated remains 
poorly understood. We identified a novel interaction between nuclear actin and 
HDAC 1 and HDAC 2. Nuclear actin has been previously shown to interact with a 
growing list of nuclear proteins including chromatin remodeling complexes, 
transcription factors and RNA polymerases. We find that monomeric actin is able 
to bind the class I HDAC complex. Furthermore, increasing the concentration of 
actin in HeLa nuclear extracts was able to suppress overall HDAC function. 
Conversely, polymerizing nuclear actin increased HDAC activity and decreased 
histone acetylation. Moreover, the interaction between class I HDACs and nuclear 
actin was found to be activity dependent. Together, our data suggest nuclear 
actin is able to regulate HDAC 1 and 2 activity.