The fully linked HTML version of this article has now been published.
JCS ePress
online publication date 27 Jul 2004
doi: 10.1242/jcs.01289
Research Article
Analysis of Smad nucleocytoplasmic shuttling in living cells
Francisco J. Nicolás,
Karolien De Bosscher,
Bernhard Schmierer,
and
Caroline S. Hill*
* Author for correspondence (e-mail: caroline.hill{at}cancer.org.uk)
Transforming growth factor
(TGF-
) signalling leads to phosphorylation and activation of receptor-regulated Smad2 and Smad3, which form complexes with Smad4 and accumulate in the nucleus. The Smads, however, do not seem to reside statically in the cytoplasm in the absence of signalling or in the nucleus upon TGF-
stimulation, but have been suggested to shuttle continuously between these cellular compartments in both the absence and presence of TGF-
. Here we investigate this nucleocytoplasmic shuttling in detail in living cells using fusions of Smad2 and Smad4 with enhanced GFP. We first establish that the GFPSmad fusions behave like wild-type Smads in a variety of cellular assays. We go on to demonstrate directly, using photobleaching experiments, that Smad2 and Smad4 shuttle between the cytoplasm and nucleus in both TGF-
-induced cells and in uninduced cells. In uninduced cells, GFPSmad2 is less mobile in the cytoplasm than is GFPSmad4, suggesting that it may be tethered there. In addition, we show that both GFPSmad2 and GFPSmad4 undergo a substantial decrease in mobility in the nucleus upon TGF-
stimulation, suggesting that active complexes of Smads are tethered in the nucleus, whereas unactivated Smads are more freely diffusible. We propose that regulated cytoplasmic and nuclear retention may play a role in determining the distribution of Smads between the cytoplasm and the nucleus in both uninduced cells and upon TGF-
induction.
This article has been cited by other articles:

|
 |

|
 |
 
A. C. Daly, R. A. Randall, and C. S. Hill
Transforming Growth Factor {beta}-Induced Smad1/5 Phosphorylation in Epithelial Cells Is Mediated by Novel Receptor Complexes and Is Essential for Anchorage-Independent Growth
Mol. Cell. Biol.,
November 15, 2008;
28(22):
6889 - 6902.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W. O. Miles, E. Jaffray, S. G. Campbell, S. Takeda, L. J. Bayston, S. P. Basu, M. Li, L. A. Raftery, M. P. Ashe, R. T. Hay, et al.
Medea SUMOylation restricts the signaling range of the Dpp morphogen in the Drosophila embryo
Genes & Dev.,
September 15, 2008;
22(18):
2578 - 2590.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Batut, B. Schmierer, J. Cao, L. A. Raftery, C. S. Hill, and M. Howell
Two highly related regulatory subunits of PP2A exert opposite effects on TGF-{beta}/Activin/Nodal signalling
Development,
September 1, 2008;
135(17):
2927 - 2937.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. Schmierer, A. L. Tournier, P. A. Bates, and C. S. Hill
Mathematical modeling identifies Smad nucleocytoplasmic shuttling as a dynamic signal-interpreting system
PNAS,
May 6, 2008;
105(18):
6608 - 6613.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T.-V. Do, L. A. Kubba, H. Du, C. D. Sturgis, and T. K. Woodruff
Transforming Growth Factor-{beta}1, Transforming Growth Factor-{beta}2, and Transforming Growth Factor-{beta}3 Enhance Ovarian Cancer Metastatic Potential by Inducing a Smad3-Dependent Epithelial-to-Mesenchymal Transition
Mol. Cancer Res.,
May 1, 2008;
6(5):
695 - 705.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Saka, A. I. Hagemann, O. Piepenburg, and J. C. Smith
Nuclear accumulation of Smad complexes occurs only after the midblastula transition in Xenopus
Development,
December 1, 2007;
134(23):
4209 - 4218.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. DeLotto, Y. DeLotto, R. Steward, and J. Lippincott-Schwartz
Nucleocytoplasmic shuttling mediates the dynamic maintenance of nuclear Dorsal levels during Drosophila embryogenesis
Development,
December 1, 2007;
134(23):
4233 - 4241.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. Xu, X. Yao, X. Chen, P. Lu, B. Zhang, and Y. T. Ip
Msk is required for nuclear import of TGF-{beta}/BMP-activated Smads
J. Cell Biol.,
September 7, 2007;
178(6):
981 - 994.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. Dai, C. Chang, X. Lin, P. Dai, L. Mei, and X.-H. Feng
Erbin Inhibits Transforming Growth Factor {beta} Signaling through a Novel Smad-Interacting Domain
Mol. Cell. Biol.,
September 1, 2007;
27(17):
6183 - 6194.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. Dai, T. Nakagami, H. Tanaka, T. Hitomi, and T. Takamatsu
Cx43 Mediates TGF-beta Signaling through Competitive Smads Binding to Microtubules
Mol. Biol. Cell,
June 1, 2007;
18(6):
2264 - 2273.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. Krieghoff, J. Behrens, and B. Mayr
Nucleo-cytoplasmic distribution of {beta}-catenin is regulated by retention.
J. Cell Sci.,
April 1, 2006;
119(Pt 7):
1453 - 1463.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Frahm, H. Hauser, and M. Koster
IFN-type-I-mediated signaling is regulated by modulation of STAT2 nuclear export
J. Cell Sci.,
March 15, 2006;
119(6):
1092 - 1104.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Kurisaki, K. Kurisaki, M. Kowanetz, H. Sugino, Y. Yoneda, C.-H. Heldin, and A. Moustakas
The Mechanism of Nuclear Export of Smad3 Involves Exportin 4 and Ran
Mol. Cell. Biol.,
February 15, 2006;
26(4):
1318 - 1332.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. C. Pache, D. W. Burton, L. J. Deftos, and R. H. Hastings
A Carboxyl Leucine-Rich Region of Parathyroid Hormone-Related Protein Is Critical for Nuclear Export
Endocrinology,
February 1, 2006;
147(2):
990 - 998.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. Schmierer and C. S. Hill
Kinetic Analysis of Smad Nucleocytoplasmic Shuttling Reveals a Mechanism for Transforming Growth Factor {beta}-Dependent Nuclear Accumulation of Smads
Mol. Cell. Biol.,
November 15, 2005;
25(22):
9845 - 9858.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Wang, W. A. Mohler, and C. Savage-Dunn
C-terminal mutants of C. elegans Smads reveal tissue-specific requirements for protein activation by TGF-{beta} signaling
Development,
August 1, 2005;
132(15):
3505 - 3513.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. B. Chen, J. G. Rud, K. Lin, and L. Xu
Nuclear Targeting of Transforming Growth Factor-{beta}-activated Smad Complexes
J. Biol. Chem.,
June 3, 2005;
280(22):
21329 - 21336.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. C. Ziegler and S. Ghosh
Regulating Inducible Transcription Through Controlled Localization
Sci. Signal.,
May 17, 2005;
2005(284):
re6 - re6.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2004