Research Project
Grant-in-Aid for Challenging Exploratory Research
The small GTPase Ran, Ras-related nuclear protein, plays important roles in multiple fundamental cellular functions such as nucleocytoplasmic transport, mitotic spindle assembly, and nuclear envelope formation, by binding to either GTP or GDP as a molecular switch. During the long-term culture of normal mammalian cells, I found that the endogenous Ran level gradually reduced in a passage-dependent manner. To examine the physiological significance of Ran reduction, I first performed small interfering RNA(siRNA)-mediated abrogation of Ran in human diploid fibroblasts. Ran-depleted cells showed several senescent phenotypes. Furthermore, I found that nuclear accumulation of importinα, which was also observed in cells treated with siRNA against CAS, a specific export factor for importinα, occurred in the Ran-depleted cells before the cells showed senescent phenotypes. Further, the CAS-depleted cells also exhibited cellular senescence. Indeed, importinα gradually accumulated in a passage-dependent manner. Thus, reduction in Ran levels causes nuclear accumulation of importinα, leading to cellular senescence in normal cells. The amount of intracellular Ran may be critically related to cell senescence. The cellular aging process may proceed through gradual regression of Ran-dependent nucleocytoplasmic transport competency.
All 2012 2011 Other
All Journal Article (27 results) (of which Peer Reviewed: 27 results) Presentation (7 results) Remarks (1 results)
Traffic
Volume: (in press)
Genes Cells
BioMol. Concepts
Commun. Integ. Biol
Volume: 5 Pages: 220-222
http://dx.doi.org/10.1038/emboj.2011.360
Cell Cycle
Volume: 10 Pages: 12-12
http://dx.doi.org/10.4161/cc.10.12.15759
Volume: 12 Issue: 11 Pages: 1468-1474
10.1111/j.1600-0854.2011.01211.x
EMBO J.
Volume: 31 Issue: 1 Pages: 83-94
10.1038/emboj.2011.360
BMC Mol. Biol.
Volume: 12 Issue: 1 Pages: 48-48
10.1186/1471-2199-12-48
Mol. Cell. Biochem.
Volume: 356 Issue: 1-2 Pages: 191-200
10.1007/s11010-011-0944-9
Exp. Cell Res
Volume: 317 Pages: 1970-1978
http://dx.doi.org/10.1016/j.yexcr.2011.05.024
FEBS J
Volume: 278 Pages: 1561-1572
Hybridoma
Volume: 30 Issue: 3 Pages: 307-309
10.1089/hyb.2011.0006
Volume: 30 Issue: 3 Pages: 303-306
10.1089/hyb.2011.0004
Am J. Respir. Cell Mol. Biol.
Volume: 45 Issue: 3 Pages: 453-458
10.1165/rcmb.2008-0393oc
J. Biol. Chem.
Volume: 286 Issue: 17 Pages: 15126-15131
10.1074/jbc.m110.213579
Cell Structure and Function
Volume: 36 Issue: 1 Pages: 57-67
10.1247/csf.10026
130004137564
FEBS Lett
Volume: 585 Pages: 791-796
http://dx.doi.org/10.1016/j.febslet.2011.02.002
Biochem. Biophys. Res. Commun.
Volume: 405 Issue: 4 Pages: 697-702
10.1016/j.bbrc.2011.01.108
FEBS J.
Volume: 278 Issue: 4 Pages: 610-621
10.1111/j.1742-4658.2010.07982.x
Volume: 278 Issue: 9 Pages: 1561-1572
10.1111/j.1742-4658.2011.08079.x
Exp.Cell Res.
Volume: 317 Issue: 14 Pages: 1970-1978
10.1016/j.yexcr.2011.05.024
Mol.Biol.Cell
Volume: 22 Issue: 19 Pages: 3715-3724
10.1091/mbc.e10-10-0809
Cell Cycle.
Volume: 10 Issue: 12 Pages: 12-12
10.4161/cc.10.12.15759
Volume: (In press)
Commun.Integ.Biol.
BioMol.Concepts
http://www.anat3.med.osaka-u.ac.jp/