[Bifunctional role of domain zinc fingers of methyl-DNA-binding protein Kaiso].

DNA methylation in mammals is one of the major epigenetic mark that associates with inactive chromatin state. Methyl-DNA-binding proteins bind methylated DNA and silence gene transcription by recruiting repression complexes. Kaiso is one of the methyl-DNA-binding proteins. It has a domain structure: N-terminal BTB/POZ domain involved in protein-protein interaction and C-terminal zinc-fingers of C2H2 type that bind methylated DNA (mCGmCG) or nonmethylated - TCCTGCNA. Here we show that Kaiso interacts with p120 catenin through zinc finger 2 and 3. This interaction has dual consequences. Firstly, binding to p120 inhibits nuclear import of Kaiso that results in most of Kaiso-p120 complexes becoming cytoplasmic. And secondly, bound p120 makes impossible interaction of the zinc fingers with methylated DNA. These modes of Kaiso modulation by p120 can open attractive perspectives in linking events on cell membrane and changes in nuclear gene expression.