In brain, Axl recruits Grb2 and the p85 regulatory subunit of PI3 kinase; in vitro mutagenesis defines the requisite binding sites for downstream Akt activation

Jason G. Weinger, Pouyan Gohari, Ying Yan, Jonathan M. Backer, Brian Varnum, Bridget Shafit-Zagardo

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Axl is a receptor tyrosine kinase implicated in cell survival following growth factor withdrawal and other stressors. The binding of Axl's ligand, growth arrest-specific protein 6 (Gas6), results in Axl autophosphorylation, recruitment of signaling molecules, and activation of downstream survival pathways. Pull-down assays and immunoprecipitations using wildtype and mutant Axl transfected cells determined that Axl directly binds growth factor receptor-bound protein 2 (Grb2) at pYVN and the p85 subunit of phosphatidylinositol-3 kinase (PI3 kinase) at two pYXXM sites (pY779 and pY821). Also, p85 can indirectly bind to Axl via an interaction between p85's second proline-rich region and the N-terminal SH3 domain of Grb2. Further, Grb2 and p85 can compete for binding at the pY821VNM site. Gas6-stimulation of Axl-transfected COS7 cells recruited activated PI3 kinase and phosphorylated Akt. An interaction between Axl, p85 and Grb2 was confirmed in brain homogenates, enriched populations of O4+ oligodendrocytes, and O4- flow-through prepared from day 10 mouse brain, indicating that cells with active Gas6/Axl signal through Grb2 and the PI3 kinase/Akt pathways.

Original languageEnglish (US)
Pages (from-to)134-146
Number of pages13
JournalJournal of Neurochemistry
Volume106
Issue number1
DOIs
StatePublished - Jul 2008

Fingerprint

GRB2 Adaptor Protein
Phosphatidylinositol 3-Kinase
Mutagenesis
Brain
Chemical activation
Binding Sites
src Homology Domains
Oligodendroglia
Receptor Protein-Tyrosine Kinases
Immunoprecipitation
Proline
Assays
Cell Survival
Intercellular Signaling Peptides and Proteins
Cells
In Vitro Techniques
Ligands
Molecules
Population
growth arrest-specific protein 6

Keywords

  • Akt signaling
  • Axl receptor tyrosine kinase
  • Growth arrest-specific protein 6
  • Growth factor receptor-bound protein 2
  • Oligodendrocytes
  • p85 subunit of phosphatidylinositol-3 kinase

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Cite this

In brain, Axl recruits Grb2 and the p85 regulatory subunit of PI3 kinase; in vitro mutagenesis defines the requisite binding sites for downstream Akt activation. / Weinger, Jason G.; Gohari, Pouyan; Yan, Ying; Backer, Jonathan M.; Varnum, Brian; Shafit-Zagardo, Bridget.

In: Journal of Neurochemistry, Vol. 106, No. 1, 07.2008, p. 134-146.

Research output: Contribution to journalArticle

@article{4d6a305df1bd4e6f946f20f0014cfa1b,
title = "In brain, Axl recruits Grb2 and the p85 regulatory subunit of PI3 kinase; in vitro mutagenesis defines the requisite binding sites for downstream Akt activation",
abstract = "Axl is a receptor tyrosine kinase implicated in cell survival following growth factor withdrawal and other stressors. The binding of Axl's ligand, growth arrest-specific protein 6 (Gas6), results in Axl autophosphorylation, recruitment of signaling molecules, and activation of downstream survival pathways. Pull-down assays and immunoprecipitations using wildtype and mutant Axl transfected cells determined that Axl directly binds growth factor receptor-bound protein 2 (Grb2) at pYVN and the p85 subunit of phosphatidylinositol-3 kinase (PI3 kinase) at two pYXXM sites (pY779 and pY821). Also, p85 can indirectly bind to Axl via an interaction between p85's second proline-rich region and the N-terminal SH3 domain of Grb2. Further, Grb2 and p85 can compete for binding at the pY821VNM site. Gas6-stimulation of Axl-transfected COS7 cells recruited activated PI3 kinase and phosphorylated Akt. An interaction between Axl, p85 and Grb2 was confirmed in brain homogenates, enriched populations of O4+ oligodendrocytes, and O4- flow-through prepared from day 10 mouse brain, indicating that cells with active Gas6/Axl signal through Grb2 and the PI3 kinase/Akt pathways.",
keywords = "Akt signaling, Axl receptor tyrosine kinase, Growth arrest-specific protein 6, Growth factor receptor-bound protein 2, Oligodendrocytes, p85 subunit of phosphatidylinositol-3 kinase",
author = "Weinger, {Jason G.} and Pouyan Gohari and Ying Yan and Backer, {Jonathan M.} and Brian Varnum and Bridget Shafit-Zagardo",
year = "2008",
month = "7",
doi = "10.1111/j.1471-4159.2008.05343.x",
language = "English (US)",
volume = "106",
pages = "134--146",
journal = "Journal of Neurochemistry",
issn = "0022-3042",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - In brain, Axl recruits Grb2 and the p85 regulatory subunit of PI3 kinase; in vitro mutagenesis defines the requisite binding sites for downstream Akt activation

AU - Weinger, Jason G.

AU - Gohari, Pouyan

AU - Yan, Ying

AU - Backer, Jonathan M.

AU - Varnum, Brian

AU - Shafit-Zagardo, Bridget

PY - 2008/7

Y1 - 2008/7

N2 - Axl is a receptor tyrosine kinase implicated in cell survival following growth factor withdrawal and other stressors. The binding of Axl's ligand, growth arrest-specific protein 6 (Gas6), results in Axl autophosphorylation, recruitment of signaling molecules, and activation of downstream survival pathways. Pull-down assays and immunoprecipitations using wildtype and mutant Axl transfected cells determined that Axl directly binds growth factor receptor-bound protein 2 (Grb2) at pYVN and the p85 subunit of phosphatidylinositol-3 kinase (PI3 kinase) at two pYXXM sites (pY779 and pY821). Also, p85 can indirectly bind to Axl via an interaction between p85's second proline-rich region and the N-terminal SH3 domain of Grb2. Further, Grb2 and p85 can compete for binding at the pY821VNM site. Gas6-stimulation of Axl-transfected COS7 cells recruited activated PI3 kinase and phosphorylated Akt. An interaction between Axl, p85 and Grb2 was confirmed in brain homogenates, enriched populations of O4+ oligodendrocytes, and O4- flow-through prepared from day 10 mouse brain, indicating that cells with active Gas6/Axl signal through Grb2 and the PI3 kinase/Akt pathways.

AB - Axl is a receptor tyrosine kinase implicated in cell survival following growth factor withdrawal and other stressors. The binding of Axl's ligand, growth arrest-specific protein 6 (Gas6), results in Axl autophosphorylation, recruitment of signaling molecules, and activation of downstream survival pathways. Pull-down assays and immunoprecipitations using wildtype and mutant Axl transfected cells determined that Axl directly binds growth factor receptor-bound protein 2 (Grb2) at pYVN and the p85 subunit of phosphatidylinositol-3 kinase (PI3 kinase) at two pYXXM sites (pY779 and pY821). Also, p85 can indirectly bind to Axl via an interaction between p85's second proline-rich region and the N-terminal SH3 domain of Grb2. Further, Grb2 and p85 can compete for binding at the pY821VNM site. Gas6-stimulation of Axl-transfected COS7 cells recruited activated PI3 kinase and phosphorylated Akt. An interaction between Axl, p85 and Grb2 was confirmed in brain homogenates, enriched populations of O4+ oligodendrocytes, and O4- flow-through prepared from day 10 mouse brain, indicating that cells with active Gas6/Axl signal through Grb2 and the PI3 kinase/Akt pathways.

KW - Akt signaling

KW - Axl receptor tyrosine kinase

KW - Growth arrest-specific protein 6

KW - Growth factor receptor-bound protein 2

KW - Oligodendrocytes

KW - p85 subunit of phosphatidylinositol-3 kinase

UR - http://www.scopus.com/inward/record.url?scp=45249119017&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=45249119017&partnerID=8YFLogxK

U2 - 10.1111/j.1471-4159.2008.05343.x

DO - 10.1111/j.1471-4159.2008.05343.x

M3 - Article

VL - 106

SP - 134

EP - 146

JO - Journal of Neurochemistry

JF - Journal of Neurochemistry

SN - 0022-3042

IS - 1

ER -