Amyloid precursor protein modulates ERK-1 and -2 signaling.

Abstract

The amyloid precursor protein (APP) is a transmembrane protein with a short cytoplasmic tail whose physiological function is unclear, although it is well documented that the proteolytic processing of APP could influence the development of Alzheimer's disease (AD) through the formation of membrane-bound C-terminal fragments (CTFs) and of beta-amyloid peptides (Abeta). We have recently shown that tyrosine-phosphorylated APP and CTFs may interact with Grb2 and ShcA adaptor proteins and that this coupling occurs at a higher extent in AD subjects only. To study the interaction between APP or CTFs and ShcA/Grb2 and to investigate their molecular target we have used as experimental model two different cell lines: H4 human neuroglioma cells and APP/APLP null mouse embryonic fibroblast cells (MEFs). Here we show that in H4 cells APP interacts with Grb2; conversely in APP/APLP-null MEF cells this interaction is possible only after the reintroduction of human APP by transfection. We have also shown that in MEF cells the transfection of a plasmid encoding for human APP wild-type enhances the phosphorylation of ERK-1 and -2 as revealed by Western blotting and immunofluorescence experiments. Finally, also in H4 cells the overexpression of APP upregulates the levels of phospho-ERK-1 and -2. In summary our data suggest that APP may influence phospho-ERK-1 and -2 signaling through its binding with Grb2 and ShcA adaptors. The meaning of this event is not clear, but APP interaction with these adaptors could be relevant to regulate mitogenic pathway.

• Authors: Valentina Venezia, Mario Nizzari, Emanuela Repetto, Elisabetta Violani, Alessandro Corsaro, Stefano Thellung, Valentina Villa, Pia Carlo, Gennaro Schettini, Tullio Florio, Claudio Russo
• Journal: Annals of the New York Academy of Sciences (Ann N Y Acad Sci) Vol. 1090 Pg. 455-65 (Dec 2006) ISSN: 0077-8923 [Print] United States
• PMID: 17384289 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amyloid beta-Protein Precursor
• Mitogen-Activated Protein Kinase 1
• Mitogen-Activated Protein Kinase 3

Topics

• Amyloid beta-Protein Precursor (genetics, physiology)
• Animals
• Cell Line
• Fluorescent Antibody Technique
• Mice
• Microscopy, Confocal
• Mitogen-Activated Protein Kinase 1 (metabolism)
• Mitogen-Activated Protein Kinase 3 (metabolism)
• Signal Transduction (physiology)