A novel human zinc finger protein ZNF540 interacts with MVP and inhibits transcriptional activities of the ERK signal pathway.

Mitogen-activated protein kinases (MAPKs) are evolutionarily conserved enzymes in cell signal transduction. Previous studies revealed that zinc finger proteins are involved in the regulation of the MAPK signaling pathways. Here we report the identification and characterization of a novel human zinc finger protein, ZNF540. The cDNA of ZNF540 is 3.3kb, encoding 660 amino acids in the nucleus and the cytoplasm. Northern blot analysis indicates that ZNF540 is expressed in most of the fetal tissues. Overexpression of FLAG-ZNF540 in COS-7 cells represses the transcriptional activities of SRE and ELK-1, which can be relieved by siRNA. MVP, one of MAPK scaffold proteins, is identified as a potential ZNF540-binding protein. This interaction is detected by a yeast two-hybrid assay, reporter gene assays, and co-immunoprecipitation. Taken together, these results suggest that ZNF540 may act as a transcriptional repressor in MAPK signaling pathway to mediate cellular functions.