A New Member of the Amphiphysin Family Connecting Endocytosis and Signal Transduction Pathways

doi:10.1074/jbc.272.24.15101

A New Member of the Amphiphysin Family Connecting Endocytosis and Signal Transduction Pathways*

From ^‡INSERM U248, Institut Curie, 26 rue d’Ulm, 75231 Paris Cedex 05, France, ^¶INSERM U363, Institut Cochin de Génétique Moléculaire, ^**INSERM U266-URA D1500 CNRS, Université Rene Descartes, and ^‡INSERM U301, Institut de Génétique Moléculaire, Paris, France

Abstract

Src homology 3 (SH3) domains are conserved modules which participate in protein interaction by recognizing proline-rich motifs on target molecules. To identify new SH3-containing proteins, we performed a two-hybrid screen with a proline-rich region of human SOS-1. One of the specific SOS-1 interacting clones that were isolated from a mouse brain cDNA library defines a new protein that was named amphiphysin 2 because of its homology to the previously reported amphiphysin. Amphiphysin 2 is expressed in a number of mouse tissues through multiple RNA transcripts. Here, we report the amino acid sequence of a brain form of amphiphysin2 (BRAMP2) encoded by a 2.5-kilobase mRNA. BRAMP2 associates in vitro with elements of the endocytosis machinery such as α-adaptin and dynamin. On a biosensor surface, the BRAMP2/dynamin interaction appeared to be direct and partly dependent on a proline-rich sequence of dynamin. Association with dynamin was also observed in PC12 cells after cell stimulation with nerve growth factor, suggesting that amphiphysin 2 may be connected to receptor-dependent signaling pathways. This hypothesis is strengthened by the ability of BRAMP2 to interact with the p21^ras exchange factor SOS, in vitro, as a possible point of interconnection between the endocytic and signaling pathways.

Footnotes

↵* This work was supported in part by grants from Association pour la Recherche contre le Cancer (ARC), Ligue Nationale contre le Cancer (Comité de Paris), and Groupement de Recherche et d’Etudes sur les Génomes.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) U86405.
↵§ To whom correspondence should be addressed: INSERM U248, Institut Curie, 26 rue d’Ulm, 75231 Paris Cedex 05, France. Tel.: 33-1-42-34-66-43; Fax: 33-1-42-34-66-50; E-mail:leprince{at}curie.fr.
↵‖ Supported by a postdoctoral European Community fellowship.
↵1 The abbreviations used are: SH, Src homology; AA, amino acid; GST, glutathione S-transferase; mAb, monoclonal antibody; MBP, maltose-binding protein; NGF, nerve growth factor; PAGE, polyacrylamide gel electrophoresis; SPR, surface plasmon resonance; bp, base pair(s); kb, kilobase(s); Chaps, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid.
- Received February 5, 1997.
- Revision received April 9, 1997.