ZNF

ZNF stands for zinc finger protein, a large and diverse family of proteins characterized by the presence of zinc finger motifs that coordinate zinc ions and enable interactions with DNA, RNA, or proteins. The most common domain is the C2H2 zinc finger, typically arranged in tandem repeats that recognize DNA sequences; other types include C4 and C3H motifs, as well as atypical variants. Many ZNFs harbor additional domains that influence activity, localization, or interactions, such as Krüppel-associated box (KRAB) repression domains, SCAN, or BTB/POZ domains.

Functionally, zinc finger proteins frequently act as transcription factors, binding specific DNA sequences to regulate gene expression during development, differentiation, and cellular responses. KRAB-ZNFs recruit the KAP1 (TRIM28) co-repressor complex to promote chromatin condensation and transcriptional repression. Other ZNFs participate in chromatin remodeling, RNA processing, or broader protein networks. Some ZNFs serve as activators or co-factors in a context-dependent manner, and the DNA-binding specificity often derives from the arrangement and number of finger repeats.

Genomic and evolutionary aspects show that zinc finger proteins constitute one of the largest gene families in humans. The C2H2 and KRAB-ZNF subfamilies are particularly prominent. The family has undergone extensive expansion in vertebrates, which is thought to contribute to regulatory complexity and the suppression of transposable elements. Disruptions or misregulation of ZNF genes have been linked to diseases including cancer, developmental disorders, and neurological conditions. Ongoing research aims to map binding motifs, regulatory networks, and structure-function relationships using genome-wide assays and functional genomics tools.