The nonhistone chromosomal protein, H2A-specific protease, is selectively associated with nucleosomes containing histone H1.
We have determined the distribution of the nucleosomal bound nonhistone chromosomal protein, H2A-specific protease, in calf thymus and liver chromatin. The protease was unevenly distributed in chromatin with domains containing histone H1 being selectively complexed with the enzyme. Moreover, the protease had a preference for the less compact chromatin domains enriched in the H1 subtypes H1a and -c. We have demonstrated that ubiquitinated H2A is a substrate of the H2A-specific protease and that the enzyme is a serine protease which can be inactivated with protease inhibitors only after it is released from the nucleosome. Possible functions of the protease in modulating chromatin structure are discussed.
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002843:Chromatin / Q000201:enzymology; D010450:Endopeptidases / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008836:Micrococcal Nuclease / Q000378:metabolism; D009707:Nucleosomes / Q000201:enzymology*; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D011189:Potassium Chloride; D011480:Protease Inhibitors / Q000494:pharmacology; D012995:Solubility; D013950:Thymus Gland / Q000201:enzymology*; D014452:Ubiquitins / Q000378:metabolism
D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D011480:Protease Inhibitors; D014452:Ubiquitins; D010664:Phenylmethylsulfonyl Fluoride; D011189:Potassium Chloride; D008836:Micrococcal Nuclease; D010450:Endopeptidases; C021361:histone proteases