Basonuclin Is Associated With the Ribosomal RNA Genes on Human Keratinocyte Mitotic Chromosomes

Basonuclin, a zinc finger protein primarily found in keratinocytes and hair follicles, was shown to associate with chromatin throughout the cell cycle, including mitosis. The study demonstrated that during mitosis, basonuclin was linked to the short arms of acrocentric chromosomes and other loci on metaphase chromosomes in human keratinocytes. The research suggested that basonuclin's DNA target sequences on these chromosomes were likely within the promoter region of the 45S rRNA gene transcription unit. DNase I footprinting indicated that basonuclin interacted with the upstream control element of this promoter, essential for high-level transcription of rRNA genes, implying that basonuclin might function as a tissue-specific transcription factor for ribosomal RNA genes.