The fully linked HTML version of this article has now been published.
JCS ePress
online publication date 9 Mar 2004
doi: 10.1242/jcs.01027
Research Article
Unconventional protein secretion: membrane translocation of FGF-2 does not require protein unfolding
Rafael Backhaus,
Christoph Zehe,
Sabine Wegehingel,
Angelika Kehlenbach,
Blanche Schwappach,
and
Walter Nickel*
* Author for correspondence (e-mail: walter.nickel{at}urz.uni-heidelberg.de)
Endoplasmic reticulum/Golgi-dependent protein secretion depends on signal peptides that mediate membrane translocation of nascent secretory proteins into the lumen of the endoplasmic reticulum. Classical secretory proteins are transported across the membrane of the endoplasmic reticulum in an unfolded conformation, which is similar to protein import into mitochondria. This process is mediated by Sec61, the protein-conducting channel of the endoplasmic reticulum. Employing both FACS-based in vivo transport assays and confocal microscopy, we now show that fibroblast growth factor 2 (FGF-2), a pro-angiogenic mediator exported from mammalian cells by an unconventional secretory pathway, does not need to be unfolded in order to be released into the extracellular space. These findings suggest that the molecular apparatus mediating export of FGF-2 is not only distinct from classical translocation machineries in terms of molecular identity but also operates in a mechanistically distinct manner that allows membrane translocation of FGF-2 in a folded conformation.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:

|
 |

|
 |
 
L. C. Torrado, K. Temmerman, H.-M. Muller, M. P. Mayer, C. Seelenmeyer, R. Backhaus, and W. Nickel
An intrinsic quality-control mechanism ensures unconventional secretion of fibroblast growth factor 2 in a folded conformation
J. Cell Sci.,
September 15, 2009;
122(18):
3322 - 3329.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Scarpellini, R. Germack, H. Lortat-Jacob, T. Muramatsu, E. Billett, T. Johnson, and E. A. M. Verderio
Heparan Sulfate Proteoglycans Are Receptors for the Cell-surface Trafficking and Biological Activity of Transglutaminase-2
J. Biol. Chem.,
July 3, 2009;
284(27):
18411 - 18423.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W. Nickel
Unconventional secretion: an extracellular trap for export of fibroblast growth factor 2
J. Cell Sci.,
July 15, 2007;
120(14):
2295 - 2299.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Zehe, A. Engling, S. Wegehingel, T. Schafer, and W. Nickel
Cell-surface heparan sulfate proteoglycans are essential components of the unconventional export machinery of FGF-2
PNAS,
October 17, 2006;
103(42):
15479 - 15484.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. A. Lynes, K. Zaffuto, D. W. Unfricht, G. Marusov, J. S. Samson, and X. Yin
The physiological roles of extracellular metallothionein.
Experimental Biology and Medicine,
October 1, 2006;
231(9):
1548 - 1554.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Seelenmeyer, S. Wegehingel, I. Tews, M. Kunzler, M. Aebi, and W. Nickel
Cell surface counter receptors are essential components of the unconventional export machinery of galectin-1
J. Cell Biol.,
October 24, 2005;
171(2):
373 - 381.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Stegmayer, A. Kehlenbach, S. Tournaviti, S. Wegehingel, C. Zehe, P. Denny, D. F. Smith, B. Schwappach, and W. Nickel
Direct transport across the plasma membrane of mammalian cells of Leishmania HASPB as revealed by a CHO export mutant
J. Cell Sci.,
February 1, 2005;
118(3):
517 - 527.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2004