Cloning And Functional Analyses Of A Novel Human Zinc Finger Protein Gene ZNF540

Transcription factors play an essential role in controlling gene expression during cardiac and vascular pathogenesis. Identification of regulatory genes in the cardiovascular system is a necessary toward an understanding of the pathogenesis of congenital heart disease (CHD) and acquired cardiovascular diseases. The Cys2/His2 type zinc finger genes are the single largest class of transcription factors in the human genome and many numbers of the kr(u|¨)pple-like zinc finger genes have been found to be involved in cardiac development or cardiovascular diseases.In the present study, we report the identification and characterization of a novel KRAB-containing zinc-finger protein, ZNF540, from a human embryonic heart cDNA library. ZNF540 encodes a putative protein of 661amino acids. Northern analysis and Northern blot indicate that ZNF540 is expressed in various tissues at the six months embryonic development stage.In COS-7 cells, ZNF540 protein is localized to nucleus. ZNF540 is a transcription repressor by KRAB motif and zinc finger motif when fused to Gal-4 DNA-binding domain and cotranfected with VP-16. Overexpression of ZNF540 in COS-7 cells inhibits the transcriptional activities of SRE and ELK-1, suggesting that the ZNF540 protein may act as a transcriptional repressor in mitogen-activated protein kinase (MAPK) signaling pathway to mediate cellular functions. Its intereaction proteins were screened by yeast two-hybrid system and 96 blue colones were obtained. The results of sequence indicated that one of the clones is MVP. Co-immunoprecipitation experiment showed that MVP may intereact with ZNF540.