Receptors are among the most extensively regulated cell surface components because they constitute the primary means by which cells perceive their environment. Epidermal growth factor receptors that contain intrinsic protein tyrosine kinase a activity are vectorially transported to basolateral surfaces of polarized cells and are diffusely distributed on cell surfaces. Receptors are activated by ligand binding and signaling is attenuated by occupancy-induced internalization and downregulation. Analysis of mutant EGFR indicates 3 features which distinguish internalization of these signaling receptors from that of nutrient receptors: the process is occupancy-induced, it requires activation of the intrinsic enzyme activity of the receptor and it depends on a combination of sequence codes located in the C'terminus. Intracellular trafficking is distinct because EGFR are segregated for targeting to lysosomes. We propose to use the EGFR to define mechanisms which carry out each of these processes that determine EGFR concentration and cell responses. A series of mutant EGFR will be constructed to precisely identify sequence codes that specify high affinity internalization. Mutants will test the importance of structures formed by active sequences and the importance of side chain interactions for their function. These receptor mutants will be used to define determinants of vectorial targeting to basolateral membranes-both sequence codes and tyrosine kinase activity. A second series of kinase-active, internalization competent EGFR mutants will be used to define sequences that specify endosomal sorting to lysosomes. Identified sorting sequences will also be analyzed in the context of C' terminally truncated EGFR that lack kinase-active domains. We will constitute endocytosis and sorting in vitro to investigate mechanisms through which EGFR sequence and tyrosine kinase activity operate in these processes. Proteins that interact with ligand-activated EGFR via endocytic codes and are tyrosine phosphorylated will be characterized. Proteins that interact with EGFR via lysosomal targeting codes will also be characterized. Mechanisms defined for EGFR are proposed to operate for the extended receptor tyrosine kinase gene family.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Program Projects (P01)
Project #
5P01CA058689-05
Application #
6237383
Study Section
Project Start
1997-06-20
Project End
1998-05-31
Budget Start
1996-10-01
Budget End
1997-09-30
Support Year
5
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of California San Diego
Department
Type
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Chen, Yao; Lin, Ping; Qiu, Suimin et al. (2007) Autoantibodies to Ca2+ binding protein Calnuc is a potential marker in colon cancer detection. Int J Oncol 30:1137-44
Sciorra, Vicki A; Audhya, Anjon; Parsons, Ainslie B et al. (2005) Synthetic genetic array analysis of the PtdIns 4-kinase Pik1p identifies components in a Golgi-specific Ypt31/rab-GTPase signaling pathway. Mol Biol Cell 16:776-93
Zhong, Qi; Watson, Martin J; Lazar, Cheri S et al. (2005) Determinants of the endosomal localization of sorting nexin 1. Mol Biol Cell 16:2049-57
Audhya, Anjon; Loewith, Robbie; Parsons, Ainslie B et al. (2004) Genome-wide lethality screen identifies new PI4,5P2 effectors that regulate the actin cytoskeleton. EMBO J 23:3747-57
Rudge, Simon A; Anderson, Deborah M; Emr, Scott D (2004) Vacuole size control: regulation of PtdIns(3,5)P2 levels by the vacuole-associated Vac14-Fig4 complex, a PtdIns(3,5)P2-specific phosphatase. Mol Biol Cell 15:24-36
Katzmann, David J; Sarkar, Srimonti; Chu, Tony et al. (2004) Multivesicular body sorting: ubiquitin ligase Rsp5 is required for the modification and sorting of carboxypeptidase S. Mol Biol Cell 15:468-80
Alam, Steven L; Sun, Ji; Payne, Marielle et al. (2004) Ubiquitin interactions of NZF zinc fingers. EMBO J 23:1411-21
Lazar, Cheri S; Cresson, Catherine M; Lauffenburger, Douglas A et al. (2004) The Na+/H+ exchanger regulatory factor stabilizes epidermal growth factor receptors at the cell surface. Mol Biol Cell 15:5470-80
Odorizzi, Greg; Katzmann, David J; Babst, Markus et al. (2003) Bro1 is an endosome-associated protein that functions in the MVB pathway in Saccharomyces cerevisiae. J Cell Sci 116:1893-903
Zheng, Bin; Berrie, Christopher P; Corda, Daniela et al. (2003) GDE1/MIR16 is a glycerophosphoinositol phosphodiesterase regulated by stimulation of G protein-coupled receptors. Proc Natl Acad Sci U S A 100:1745-50

Showing the most recent 10 out of 153 publications