CREBZF strongly activates transcription when bound to HCFC1. It suppresses the expression of HSV proteins in cells infected with the virus in a HCFC1-dependent manner. This protein suppresses the HCFC1-dependent transcriptional activation by CREB3 and reduces the amount of CREB3 in the cell. CREBZF is able to down-regulate expression of some cellular genes in CREBZF-expressing cells. Recombinant human CREBZF protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.