title: Unexpected histone H3 tail-clipping activity of glutamate dehydrogenase.
abstract: Clipping of histone tails has been reported in several organisms. However, the significance and regulation of histone tail clipping largely remains unclear. According to recent discoveries H3 clipping has been found to be involved in regulation of gene expression and chromatin dynamics. Earlier we had provided evidence of tissue-specific proteolytic processing of histone H3 in White Leghorn chicken liver nuclei. In this study we identify a novel activity of glutamate dehydrogenase (GDH) as a histone H3-specific protease in chicken liver tissue. This protease activity is regulated by divalent ions and thiol-disulfide conversion in vitro. GDH specifically clips H3 in its free as well as chromatin-bound form. Furthermore, we have found an inhibitor that inhibits the H3-clipping activity of GDH. Like previously reported proteases, GDH too may have the potential to regulate/modulate post-translational modifications of histone H3 by removing the N-terminal residues of the histone. In short, our findings identify an unexpected proteolytic activity of GDH specific to histone H3 that is regulated by redox state, ionic concentrations, and a cellular inhibitor in vitro.
authors.affiliation: Laboratory of Chromatin Biology, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462023, India.
authors.forename: Papita
authors.initials: P
authors.lastname: Mandal
authors.forename: Naveen
authors.initials: N
authors.lastname: Verma
authors.forename: Sakshi
authors.initials: S
authors.lastname: Chauhan
authors.forename: Raghuvir S
authors.initials: RS
authors.lastname: Tomar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D002645:Chickens; D002843:Chromatin / Q000378:metabolism; D057056:Cysteine Proteases / Q000378:metabolism; D004220:Disulfides; D044127:Epigenesis, Genetic; D015971:Gene Expression Regulation, Enzymologic; D005969:Glutamate Dehydrogenase / Q000097:blood / Q000378:metabolism*; D006657:Histones / Q000097:blood / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000201:enzymology; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D012492:Salts; D013438:Sulfhydryl Compounds; D013696:Temperature
chemical_list: D002843:Chromatin; D004220:Disulfides; D006657:Histones; D011994:Recombinant Proteins; D012492:Salts; D013438:Sulfhydryl Compounds; D005969:Glutamate Dehydrogenase; D057056:Cysteine Proteases
keywords: CLH3p; Chromatin; Chromatin Histone Modification; Cysteine Protease; Glutamate Dehydrogenase; H3 Protease; Histone Modification; Soluble Chromatin