TY - JOUR
T1 - Time-lapse Imaging Reveals Dynamic Relocalization of PP1γ throughout the Mammalian Cell Cycle
AU - Trinkle-Mulcahy, Laura
AU - Andrews, Paul D.
AU - Wickramasinghe, Sasala
AU - Sleeman, Judith
AU - Prescott, Alan
AU - Lam, Yun Wah
AU - Lyon, Carol
AU - Swedlow, Jason R.
AU - Lamond, Angus I.
PY - 2003/1/1
Y1 - 2003/1/1
N2 - Protein phosphatase 1 (PP1) is a ubiquitous serine/threonine phosphatase that regulates many cellular processes, including cell division. When transiently expressed as fluorescent protein (FP) fusions, the three PP1 isoforms, α, β/δ, and γ1, are active phosphatases with distinct localization patterns. We report here the establishment and characterization of HeLa cell lines stably expressing either FP-PP1γ or FP alone. Time-lapse imaging reveals dynamic targeting of FP-PP1γ to specific sites throughout the cell cycle, contrasting with the diffuse pattern observed for FP alone. FP-PP1γ shows a nucleolar accumulation during interphase. On entry into mitosis, it localizes initially at kinetochores, where it exchanges rapidly with the diffuse cytoplasmic pool. A dramatic relocalization of PP1 to the chromosome-containing regions occurs at the transition from early to late anaphase, and by telophase FP-PP1γ also accumulates at the cleavage furrow and midbody. The changing spatio-temporal distribution of PP1γ revealed using the stable PP1 cell lines implicates it in multiple processes, including nucleolar function, the regulation of chromosome segregation and cytokinesis.
AB - Protein phosphatase 1 (PP1) is a ubiquitous serine/threonine phosphatase that regulates many cellular processes, including cell division. When transiently expressed as fluorescent protein (FP) fusions, the three PP1 isoforms, α, β/δ, and γ1, are active phosphatases with distinct localization patterns. We report here the establishment and characterization of HeLa cell lines stably expressing either FP-PP1γ or FP alone. Time-lapse imaging reveals dynamic targeting of FP-PP1γ to specific sites throughout the cell cycle, contrasting with the diffuse pattern observed for FP alone. FP-PP1γ shows a nucleolar accumulation during interphase. On entry into mitosis, it localizes initially at kinetochores, where it exchanges rapidly with the diffuse cytoplasmic pool. A dramatic relocalization of PP1 to the chromosome-containing regions occurs at the transition from early to late anaphase, and by telophase FP-PP1γ also accumulates at the cleavage furrow and midbody. The changing spatio-temporal distribution of PP1γ revealed using the stable PP1 cell lines implicates it in multiple processes, including nucleolar function, the regulation of chromosome segregation and cytokinesis.
UR - http://www.scopus.com/inward/record.url?scp=0037244295&partnerID=8YFLogxK
U2 - 10.1091/mbc.E02-07-0376
DO - 10.1091/mbc.E02-07-0376
M3 - Article
C2 - 12529430
AN - SCOPUS:0037244295
SN - 1059-1524
VL - 14
SP - 107
EP - 117
JO - Molecular Biology of the Cell
JF - Molecular Biology of the Cell
IS - 1
ER -