title: Live-cell imaging of HP1α throughout the cell cycle of mouse C3H10T1/2 cells and rhythmical flickering of heterochromatin dots in interphase.
abstract: Heterochromatin protein 1 alpha (HP1α) localizes to heterochromatin in interphase and shows dynamic molecular behavior in living cells. We previously reported that during mitosis, the majority of HP1α diffused into the cytoplasm but some remained in centromere heterochromatin. Here, we further characterize the molecular behavior of HP1α throughout the cell cycle. Time-lapse imaging of DsRed-HP1α through two successive cell divisions indicated that interphase can be divided into four phases. HP1α forms heterochromatin dots in early G1, which are maintained without any apparent changes (Phase 1). However, the HP1α dots begin to diffuse into the nucleoplasm and start flickering with a rhythmical cycle (Phase 2). Then, the HP1α dots diffuse further towards the periphery of the nucleus (Phase 3), and uniformly diffuse throughout the entire nucleus (Phase 4). Rhythmical flickering of HP1α dots in the middle of interphase may be useful for following cell cycle progression in mouse living cells.
authors.affiliation: a Laboratory of Molecular Biology and Cell Informatics, Division of Bioscience and Informatics , Graduate School of Life and Environmental Sciences, Osaka Prefecture University , Osaka , Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Nakagawa
authors.forename: Ai
authors.initials: A
authors.lastname: Kawakita
authors.forename: Takashi
authors.initials: T
authors.lastname: Fukada
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugimoto
mesh_terms: D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D006570:Heterochromatin / Q000378:metabolism*; D007399:Interphase; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D057054:Molecular Imaging; D021381:Protein Transport; D013997:Time Factors
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D006570:Heterochromatin; D008164:Luminescent Proteins; C413663:fluorescent protein 583; D000090266:Chromobox Protein Homolog 5
keywords: cell cycle; heterochromatin; heterochromatin protein 1 alpha (HP1α); interphase; live cell imaging