Purification of the human histone H4 gene-specific transcription factors H4TF-1 and H4TF-2.
Transcription of the cell-cycle-regulated human histone genes increases approximately fivefold during S phase. One step toward the elucidation of the biochemical mechanisms that govern cell-cycle-regulated expression of these genes is to purify and characterize the transcription factors that regulate these promoters. Here, we describe the purification of two previously identified factors, H4TF-1 and H4TF-2, which bind the human histone H4 promoter. Purification was achieved through a combination of ion-exchange and oligonucleotide affinity chromatography. On the basis of analysis of purified fractions by SDS-polyacrylamide gels and UV cross-linking, we believe that H4TF-1 is two polypeptides of 105 and 110 kD. This factor binds to a GC-rich DNA sequence required for maximal expression of the H4 gene but does not bind to any Sp1 consensus elements tested. H4TF-2 is a 65-kD protein that binds specifically to sequences within that highly conserved H4 subtype-specific consensus promoter element. Both highly purified factors activated transcription in vitro only from H4 promoters that contained their binding sequences, demonstrating that H4TF-1 and H4TF-2 are H4-specific transcription factors that potentiate expression of this gene.
Dailey
L
L
Laboratory of Molecular Biology, Rockefeller University, New York, New York 10021.
Roberts
S B
SB
Heintz
N
N
D001483:Base Sequence; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006657:Histones / Q000235:genetics*; D006801:Humans; D008745:Methylation; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins; D016329:Sp1 Transcription Factor; D013698:Templates, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification*; D014466:Ultraviolet Rays
D004268:DNA-Binding Proteins; C059062:H4TF-1 protein, human; C442219:HINFP protein, human; D006657:Histones; D015345:Oligonucleotide Probes; D012097:Repressor Proteins; D016329:Sp1 Transcription Factor; D014157:Transcription Factors