The Plant HomeoDomain (PHD) finger proteins (PHFs) are members of zinc finger protein (ZNF) superfamily. They are regulatory proteins in nucleus and cytoplasm and are frequently associated with chromatin-mediated transcriptional regulation [24], [25]. They can specifically recognize and bind to the tri-methylated lysines (e.g., H3K4me3 or H3K9me3) on histones, and regulate their methylation status. PHF3 is ubiquitously expressed in normal tissues including brain. It has been reported that alcohol abuse could significantly up-regulate the gene expression level of PHF3 in the frontal cortex in alcoholics [26].
