Fig. 4

Hypothetical model for the MeCP2 distribution within the neuronal chromatin organization. MeCP2 is sparsely distributed in the chromatin fibers in the nucleoplasm binding to DNA methylated sites that are depleted of H1. An important fraction of MeCP2 binds preferentially to the periphery of chromocenters/nucleoli. Upon micrococcal nuclease (MNase) digestion, MeCP2 is very quickly released from the insoluble pellet-able (P) chromocenter periphery and leaks through the nuclear membrane pores into the SI fraction (see Fig. 2). MeCP2 associated to nucleosomes is also released from nuclear chromatin fibers (SE fraction), albeit at a much lower level as indicated by the thickness of the arrows. nl: mononucleosome