[Progress in the study of KRAB zinc finger protein]

The zinc finger proteins containing the Kruppel-associated box domain (KRAB) constitute the largest single family of transcriptional regulators in mammals. Many genes encoding members of this family are arranged in clusters. KRAB-containing proteins are characterized by the presence of 4 and over 30 C2H2 zinc-finger motifs and a KRAB domain near the amino terminus of the protein. KRAB domain behaving as a protein-protein interaction domain could bind to corepressor proteins and/or transcription factors, and that the KRAB-containing proteins could act as a repressor or corepressor and play a key role in transcriptional repression. Members of the family are involved in embryonic development, cell differentiation, cell proliferation, apoptosis, neoplastic transformation and cell cycle regulation.