Cell type-specific expression of a human histone H1 gene.

The expression of a human histone H1 gene (Hh8c H1) was studied in several different human cell lines. Nuclease S1 analysis revealed that this gene is expressed at high levels in KB cells and that it is regulated during the cell cycle, but that it is not expressed in several other human cell lines (HeLa, HEK, 293, and Hep G2). The differential expression of the Hh8c H1 gene in vivo was not due to gross chromosomal rearrangements or to activation of the entire histone gene cluster at this genomic locus. Thus, the cell type-specific expression of this human H1 gene must result from either critical differences in the promoter sequences of this gene in KB and HeLa cells, or from cell-specific utilization of trans-acting transcription factors.