Modulation of Heterochromatin Protein 1 Dynamics in Primary Mammalian Cells

• Published in: Science (American Association for the Advancement of Science) Vol. 299; no. 5607; pp. 719 - 721
• Main Authors: Festenstein, Richard, Pagakis, Stamatis N., Hiragami, Kyoko, Lyon, Debbie, Verreault, Alain, Sekkali, Belaid, Kioussis, Dimitris
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 31-01-2003; The American Association for the Advancement of Science
• Subjects: Animals; Binding Sites; Biological and medical sciences; Bleaching; Cells, Cultured; Cellular biology; Chromatin; Chromosomal Proteins, Non-Histone - metabolism; Deoxyribonucleic acid; Dimerization; DNA; Euchromatin; Euchromatin - metabolism; Fluorescence; Fluorescence Recovery After Photobleaching; Fundamental and applied biological sciences. Psychology; Gene expression; Genetics; Heterochromatin; Heterochromatin - metabolism; Histones; Histones - metabolism; Kinetics; Lymphocyte Activation; Medical research; Methylation; Mice; Microscopy, Confocal; Mobility; Molecular and cellular biology; Molecular genetics; Molecules; Population Distribution; Protein research; Proteins; T cells; T lymphocytes; T-Lymphocytes - metabolism; Transgenic animals; Gene silencing; Vertebrata; Chromatin; Mammalia; Mouse; Transcription; Rodentia; T-Lymphocyte; Molecular rearrangement; Gene expression; Localization
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1078694

Heterochromatin protein 1 (HP1β), a key component of condensed DNA, is strongly implicated in gene silencing and centromeric cohesion. Heterochromatin has been considered a static structure, stabilizing crucial aspects of nuclear organization and prohibiting access to transcription factors. We demonstrate here, by fluorescence recovery after photobleaching, that a green fluorescent protein-HP1β fusion protein is highly mobile within both the euchromatin and heterochromatin of ex vivo resting murine T cells. Moreover, T cell activation greatly increased this mobility, indicating that such a process may facilitate (hetero)chromatin remodeling and permit access of epigenetic modifiers and transcription factors to the many genes that are consequently derepressed.