The fully linked HTML version of this article has now been published.
Development ePress online publication date 5 Jan 2006
doi: 10.1242/dev.02219
Research article
Drosophila Cornichon acts as cargo receptor for ER export of the TGF
-like growth factor Gurken
Christian Bökel,
Sajith Dass,
Michaela Wilsch-Bräuninger,
and
Siegfried Roth*
* Author for correspondence (e-mail: siegfried.roth{at}uni-koeln.de)
Drosophila Cornichon (Cni) is the founding member of a conserved protein family that also includes Erv14p, an integral component of the COPII-coated vesicles that mediate cargo export from the yeast endoplasmic reticulum (ER). During Drosophila oogenesis, Cni is required for transport of the TGF
growth factor Gurken (Grk) to the oocyte surface. Here, we show that Cni, but not the second Drosophila Cni homologue Cni-related (Cnir), binds to the extracellular domain of Grk, and propose that Cni acts as a cargo receptor recruiting Grk into COPII vesicles. Consequently, in the absence of Cni function, Grk fails to leave the oocyte ER. Proteolytic processing of Grk still occurs in cni mutant ovaries, demonstrating that release of the active growth factor from its transmembrane precursor occurs earlier during secretory transport than described for the other Drosophila TGF homologues. Massive overexpression of Grk in a cni mutant background can overcome the requirement of Grk signalling for cni activity, confirming that cni is not essential for the production of the functional Grk ligand. However, the rescued egg chambers lack dorsoventral polarity. This demonstrates that the generation of temporally and spatially precisely coordinated Grk signals cannot be achieved by bulk flow secretion, but instead has to rely on fast and efficient ER export through cargo receptor-mediated recruitment of Grk into the secretory pathway.
This article has been cited by other articles:
|
|
|
|
 
I. Imhof, W. J. Gasper, and R. Derynck
Association of tetraspanin CD9 with transmembrane TGF{alpha} confers alterations in cell-surface presentation of TGF{alpha} and cytoskeletal organization
J. Cell Sci.,
July 1, 2008;
121(13):
2265 - 2274.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Januschke, E. Nicolas, J. Compagnon, E. Formstecher, B. Goud, and A. Guichet
Rab6 and the secretory pathway affect oocyte polarity in Drosophila
Development,
October 1, 2007;
134(19):
3419 - 3425.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
V. Barbosa, N. Kimm, and R. Lehmann
A Maternal Screen for Genes Regulating Drosophila Oocyte Polarity Uncovers New Steps in Meiotic Progression
Genetics,
August 1, 2007;
176(4):
1967 - 1977.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. P. Castro, D. Piscopo, T. Nakagawa, and R. Derynck
Cornichon regulates transport and secretion of TGF{alpha}-related proteins in metazoan cells
J. Cell Sci.,
July 15, 2007;
120(14):
2454 - 2466.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. V. Shravage, G. Altmann, M. Technau, and S. Roth
The role of Dpp and its inhibitors during eggshell patterning in Drosophila
Development,
June 15, 2007;
134(12):
2261 - 2271.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. Hoshino, T. Uchida, T. Otsuki, S. Kawamoto, K. Okubo, M. Takeichi, and O. Chisaka
Cornichon-like Protein Facilitates Secretion of HB-EGF and Regulates Proper Development of Cranial Nerves
Mol. Biol. Cell,
April 1, 2007;
18(4):
1143 - 1152.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. Nakanishi, Y. Suda, and A. M. Neiman
Erv14 family cargo receptors are necessary for ER exit during sporulation in Saccharomyces cerevisiae
J. Cell Sci.,
March 1, 2007;
120(5):
908 - 916.
[Abstract]
[Full Text]
[PDF]
|
|
|
© The Company of Biologists Ltd 2006
