Premium
K12‐biotinylated histone H4 is enriched in human telomeric repeats
Author(s) -
Wijeratne Subhashinee Samudra Kumari,
Zempleni Janos
Publication year - 2009
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.23.1_supplement.555.2
Subject(s) - telomere , telomerase , biotinylation , heterochromatin , histone , chromatin , biology , histone h4 , microbiology and biotechnology , biochemistry , gene
Covalent modifications of histones play a role in regulating telomere attrition and cellular senescence. Biotinylation of lysine (K) residues in histones, mediated by holocarboxylase synthetase (HCS), is a novel diet‐dependent mechanism to regulate chromatin structure and gene expression. We have previously shown that biotinylation of K12 in histone H4 (H4K12bio) is a marker for heterochromatin and is enriched in pericentromeric alpha satellite repeats. Here we hypothesized that H4K12bio is also enriched in telomere repeats. We used human IMR‐90 lung fibroblasts and immortalized IMR‐90 cells overexpressing human telomerase (hTERT) to quantify H4K12bio in telomeres from young and old cells. About 30% of the histone H4 molecules in telomeres were biotinylated in position K12. The abundance of H4K12bio in telomeres decreased by 42% during telomere attrition in senescent IMR‐90 cells; overexpression of telomerase prevented the loss of H4K12bio. Possible confounders such as decreased expression of HCS and biotin transporters were formally excluded. These preliminary data suggest that H4K12bio might play a role in telomere structures. (Supported by UNL ARD Hatch Act funds, NIH DK063945, DK077816 and ES015206, USDA CSREES 2006‐35200‐17138, and NSF EPSCoR EPS‐0701892.)