In vivo Binding of Active Heat Shock Transcription Factor 1 to Human Chromosome 9 Heterochromatin during Stress

• Published in: The Journal of cell biology 2002-03, Vol.156 (5), p.775-781
• Main Authors: Jolly, Caroline, Konecny, Lara, Grady, Deborah L., Kutskova, Yulia A., Cotto, José J., Morimoto, Richard I., Claire Vourc'h
• Format: Article
• Language: English
• Subjects: Antibodies; Artificial satellites; Binding Sites - genetics; Cell Nucleus - genetics; Cell Nucleus - metabolism; Cells, Cultured; Cellular biology; chromosome 9; Chromosomes; Chromosomes, Human, Pair 9 - genetics; Cytoplasmic Granules - genetics; Cytoplasmic Granules - metabolism; Deoxyribonucleic acid; DNA; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Female; Fluorescent Antibody Technique; Fluorescent antibody techniques; Genes; heat shock factor 1; Heat Shock Transcription Factors; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; HeLa cells; Heterochromatin; Heterochromatin - genetics; HSF1 protein; Humans; Microsatellite Repeats - genetics; Protein Structure, Tertiary - genetics; Proteins; Shock heating; Space probes; Stress, Physiological - genetics; Stress, Physiological - metabolism; Transcription Factors
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.200109018

Activation of the mammalian heat shock transcription factor (HSF)1 by stress is a multistep process resulting in the transcription of heat shock genes. Coincident with these events is the rapid and reversible redistribution of HSF1 to discrete nuclear structures termed HSF1 granules, whose function is still unknown. Key features are that the number of granules correlates with cell ploidy, suggesting the existence of a chromosomal target. Here we show that in humans, HSF1 granules localize to the 9q11-q12 heterochromatic region. Within this locus, HSF1 binds through direct DNA-protein interaction with a nucleosome-containing subclass of satellite III repeats. HSF1 granule formation only requires the DNA binding competence and the trimerization of the factor. This is the first example of a transcriptional activator that accumulates transiently and reversibly on a chromosome-specific heterochromatic locus.