'Homology region' (with Psc and Bmi-1) containing a RING finger motifc Zinc finger that binds to DNA at 'GCCAT'; a conserved domain (aa 118-172) interacts with PC Zinc finger homologous to that of PHO that binds to the same DNA motif as PHO

Zinc finger, Q-rich domain Genetically interacts with PCNA,A-rich domaind

Q-rich domain, A-rich domain

PHD fingers, chromodomains,ATPase domain, HMG-like motif, myb-like motif

BTB-POZ domain, Psq domain; binds to 'GAGAG' DNA motif Chromodomain; reported to interact with E(Z), ESC and GAFe HMG box proteinf

Relevant references that are not discussed in the text are listed here: a Peterson et al. (1997) b Mollaaghababa et al. (2001) c Brunk et al. (1991) d Yamamoto et al. (1997) e Salvaing et al. (2003) f Decoville et al. (2001)

Originally, a 600-kDa complex was isolated (Ng et al. 2000; Tie et al. 2001). This complex was shown to contain the ESC and E(Z) proteins as well as the Drosophila HDAC1 homologue Rpd3, the histone binding protein p55 and the Su(Z)12 PcG member (Czermin et al. 2002; Muller et al. 2002). In contrast to the other proteins, Rpd3 may be loosely associated with this complex (Kuzmichev et al. 2002). Later, a larger complex of 1 MDa was purified and shown to contain the PCL protein in addition to the members cited above (Tie et al. 2003). This is consistent with previous two-hybrid data, showing a direct interaction between PCL protein and E(Z) (O'Connell et al. 2001). The apparent discrepancy in composition of the ESC/E(Z) complex probably depends on its dynamic composition during development (Furuyama et al. 2003). In particular, the ESC product is deposited into the egg, and expressed only during embryogenesis. Thus, at larval stages the complex undergoes a major compositional change (Furuyama et al. 2003). How this change affects its regulatory function remains to be studied.

0 0

Post a comment