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An Irreversible Modification of Histone H3 ‐ Identification and Characterization of Histone H3‐specific Protease from Chicken Liver
Author(s) -
Chaturvedi Madan Mohan,
Purohit Jogeswar S,
Tomar Raghuvir Singh,
Panigrahi Anil K
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb64
Subject(s) - histone h3 , histone , proteolysis , biochemistry , chromatin , nad+ kinase , histone methyltransferase , chemistry , enzyme , biology , dna
Regulated removal of N‐terminal tails of histones would constitute an irreversible type of modification. A novel histone H3 specific modifying enzyme from chicken liver nuclei was purified that specifically cleaved histone H3 in vitro and generated a faster migrating histone H3 band. The enzyme named H3ase was sequenced with the help of MALDI‐MS & PSD and was found to align with a known NAD+‐dependent dehydrogenase (NDH). The peptide substrates against the N‐terminus histone H3 could compete with H3ase activity, building the possibility that probably, H3ase modified histone H3 in the N‐terminus. Site of proteolysis was mapped using bacterially expressed recombinant histone H3. The cleaved products corresponded to polypeptides lacking 2, 4 and 8 amino acid residues from the N‐terminus, respectively. The mechanism of proteolysis is still unknown. Efforts are being taken to evaluate the status of H3 proteolysis in chromatin level and to find out its physiological importance. This research work was supported by research grants from Department of Science and Technology, Government of India, New Delhi (Grant no. SR/SO/BB‐38/2002), and University of Delhi, India.