AEBP2 as a potential targeting protein for Polycomb Repression Complex PRC2.

AEBP2 is a zinc finger protein that has been shown to interact with the mammalian Polycomb Repression Complex 2 (PRC2). In the current study, we characterized this unknown protein and tested its potential targeting roles for the PRC2. AEBP2 is an evolutionarily well-conserved gene that is found in the animals ranging from flying insects to mammals. The transcription of mammalian AEBP2 is driven by two alternative promoters and produces at least two isoforms of the protein. These isoforms show developmental stage-specific expression patterns: the adult-specific larger form (51 kDa) and the embryo-specific smaller form (32 kDa). The AEBP2 protein binds to a DNA-binding motif with an unusual bipartite structure, CTT(N)15-23cagGCC with lower-case being less critical. A large fraction of AEBP2's target loci also map closely to the known target loci of the PRC2. In fact, many of these loci are co-occupied by the two proteins, AEBP2 and SUZ12. This suggests that AEBP2 is most likely a targeting protein for the mammalian PRC2 complex.