The relative enrichment of K12Bio H4 and HCS at SMVT promoter loci increases in response to biotin supplementation in wild-type cells but not in HCS-deficient cells. Wild-type cells and HCS-deficient cells were cultured in biotin-defined media for 5 weeks. Chromatin was immunoprecipitated using antibodies to K12Bio H4, K9Me2 H3, K4Me3 H3, and HCS (C-terminus), and DNA was quantified by PCR. (A) Relative enrichment of SMVT promoter 1 sequences by immunoprecipitation, using input DNA as denominator. (B) Relative enrichment of SMVT promoter 2 sequences by immunoprecipitation, using input DNA as denominator. Values are means ±S.D. a,b,c,dBars not sharing the same superscript are significantly different for the same antibody (P<.05, n=3–4).