MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Johannessen, L. E.
Right arrow Articles by Stang, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Johannessen, L. E.
Right arrow Articles by Stang, E.

Next Article 

Molecular and Cellular Biology, January 2006, p. 389-401, Vol. 26, No. 2
0270-7306/06/$08.00+0     doi:10.1128/MCB.26.2.389-401.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Activation of the Epidermal Growth Factor (EGF) Receptor Induces Formation of EGF Receptor- and Grb2-Containing Clathrin-Coated Pits

Lene E. Johannessen,{dagger} Nina Marie Pedersen,{dagger} Ketil Winther Pedersen, Inger Helene Madshus,* and Espen Stang

Institute of Pathology, University of Oslo, Rikshospitalet, N-0027 Oslo, Norway

Received 18 March 2005/ Returned for modification 3 May 2005/ Accepted 26 October 2005

In HeLa cells depleted of adaptor protein 2 complex (AP2) by small interfering RNA (siRNA) to the µ2 or {alpha} subunit or by transient overexpression of an AP2 sequestering mutant of Eps15, endocytosis of the transferrin receptor (TfR) was strongly inhibited. However, epidermal growth factor (EGF)-induced endocytosis of the EGF receptor (EGFR) was inhibited only in cells where the {alpha} subunit had been knocked down. By immunoelectron microscopy, we found that in AP2-depleted cells, the number of clathrin-coated pits was strongly reduced. When such cells were incubated with EGF, new coated pits were formed. These contained EGF, EGFR, clathrin, and Grb2 but not the TfR. The induced coated pits contained the {alpha} subunit, but labeling density was reduced compared to control cells. Induction of clathrin-coated pits required EGFR kinase activity. Overexpression of Grb2 with inactivating point mutations in N- or C-terminal SH3 domains or in both SH3 domains inhibited EGF-induced formation of coated pits efficiently, even though Grb2 SH3 mutations did not block activation of mitogen-activated protein kinase (MAPK) or phosphatidylinositol 3-kinase (PI3K). Our data demonstrate that EGFR-induced signaling and Grb2 are essential for formation of clathrin-coated pits accommodating the EGFR, while activation of MAPK and PI3K is not required.

* Corresponding author. Mailing address: Institute of Pathology, The University of Oslo, Rikshospitalet, N-0027 Oslo, Norway. Phone: 47 23073536. Fax: 47 23071511. E-mail: i.h.madshus{at}labmed.uio.no.

{dagger} L.E.J. and N.M.P. contributed equally to this work.

Molecular and Cellular Biology, January 2006, p. 389-401, Vol. 26, No. 2
0022-538X/06/$08.00+0     doi:10.1128/MCB.26.2.389-401.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2006 by the American Society for Microbiology. All rights reserved.