Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin

Chimaerins are a family of GTPase activating proteins (GAPs) for the small G-protein Rac that have gained recent attention due to their important roles in development, cancer, neuritogenesis, and T-cell function. Like protein kinase C isozymes, chimaerins possess a C1 domain capable of binding phorb...

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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v283_n50_p35247_ColonGonzalez
http://hdl.handle.net/20.500.12110/paper_00219258_v283_n50_p35247_ColonGonzalez
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spelling paper:paper_00219258_v283_n50_p35247_ColonGonzalez2023-06-08T14:43:29Z Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin Amines Amino acids Binding energy Binding sites Bioactivity Biochemistry Cell membranes Cytology Esterification Esters Gallium alloys Glycerol Growth (materials) Ligands Organic acids Organic compounds Peptides Pneumatic control equipment Activating proteins C1 domains Cell functions Cell migrations Diacylglycerol Epidermal growth factors In vitro Inactive conformations Ligand bindings Lipid second messengers Membrane associations Modeling analysis Neuritogenesis Phorbol esters Phospholipase Plasma membranes Protein kinases Terminal regions Chemical activation chimerin chimerin alpha 2 epidermal growth factor guanosine triphosphatase activating protein phorbol 13 acetate 12 myristate Rac protein unclassified drug article binding site cell membrane human human cell priority journal protein analysis protein domain protein function protein localization Animals Cercopithecus aethiops Chimerin 1 COS Cells Epidermal Growth Factor GTPase-Activating Proteins Hela Cells Humans Mutation Protein Binding Protein Conformation Protein Structure, Tertiary Protein Transport rac GTP-Binding Proteins Type C Phospholipases Chimaerins are a family of GTPase activating proteins (GAPs) for the small G-protein Rac that have gained recent attention due to their important roles in development, cancer, neuritogenesis, and T-cell function. Like protein kinase C isozymes, chimaerins possess a C1 domain capable of binding phorbol esters and the lipid second messenger diacylglycerol (DAG) in vitro. Here we identified an autoinhibitory mechanism in α2-chimaerin that restricts access of phorbol esters and DAG, thereby limiting its activation. Although phorbol 12-myristate 13-acetate (PMA) caused limited translocation of wild-type α2-chimaerin to the plasma membrane, deletion of either N- or C-terminal regions greatly sensitize α2-chimaerin for intracellular redistribution and activation. Based on modeling analysis that revealed an occlusion of the ligand binding site in the α2-chimaerin C1 domain, we identified key amino acids that stabilize the inactive conformation. Mutation of these sites renders α2-chimaerin hypersensitive to C1 ligands, as reflected by its enhanced ability to translocate in response to PMA and to inhibit Rac activity and cell migration. Notably, in contrast to PMA, epidermal growth factor promotes full translocation of α2-chimaerin in a phospholipase C-dependent manner, but not of a C1 domain mutant with reduced affinity for DAG (P216A-α2- chimaerin). Therefore, DAG generation and binding to the C1 domain are required but not sufficient for epidermal growth factor-induced α2-chimaerin membrane association. Our studies suggest a role for DAG in anchoring rather than activation of α2-chimaerin. Like other DAG/phorbol ester receptors, including protein kinase C isozymes, α2-chimaerin is subject to autoinhibition by intramolecular contacts, suggesting a highly regulated mechanism for the activation of this Rac-GAP. © 2008 by The American Society for Biochemistry and Molecular Biology, Inc. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v283_n50_p35247_ColonGonzalez http://hdl.handle.net/20.500.12110/paper_00219258_v283_n50_p35247_ColonGonzalez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Amines
Amino acids
Binding energy
Binding sites
Bioactivity
Biochemistry
Cell membranes
Cytology
Esterification
Esters
Gallium alloys
Glycerol
Growth (materials)
Ligands
Organic acids
Organic compounds
Peptides
Pneumatic control equipment
Activating proteins
C1 domains
Cell functions
Cell migrations
Diacylglycerol
Epidermal growth factors
In vitro
Inactive conformations
Ligand bindings
Lipid second messengers
Membrane associations
Modeling analysis
Neuritogenesis
Phorbol esters
Phospholipase
Plasma membranes
Protein kinases
Terminal regions
Chemical activation
chimerin
chimerin alpha 2
epidermal growth factor
guanosine triphosphatase activating protein
phorbol 13 acetate 12 myristate
Rac protein
unclassified drug
article
binding site
cell membrane
human
human cell
priority journal
protein analysis
protein domain
protein function
protein localization
Animals
Cercopithecus aethiops
Chimerin 1
COS Cells
Epidermal Growth Factor
GTPase-Activating Proteins
Hela Cells
Humans
Mutation
Protein Binding
Protein Conformation
Protein Structure, Tertiary
Protein Transport
rac GTP-Binding Proteins
Type C Phospholipases
spellingShingle Amines
Amino acids
Binding energy
Binding sites
Bioactivity
Biochemistry
Cell membranes
Cytology
Esterification
Esters
Gallium alloys
Glycerol
Growth (materials)
Ligands
Organic acids
Organic compounds
Peptides
Pneumatic control equipment
Activating proteins
C1 domains
Cell functions
Cell migrations
Diacylglycerol
Epidermal growth factors
In vitro
Inactive conformations
Ligand bindings
Lipid second messengers
Membrane associations
Modeling analysis
Neuritogenesis
Phorbol esters
Phospholipase
Plasma membranes
Protein kinases
Terminal regions
Chemical activation
chimerin
chimerin alpha 2
epidermal growth factor
guanosine triphosphatase activating protein
phorbol 13 acetate 12 myristate
Rac protein
unclassified drug
article
binding site
cell membrane
human
human cell
priority journal
protein analysis
protein domain
protein function
protein localization
Animals
Cercopithecus aethiops
Chimerin 1
COS Cells
Epidermal Growth Factor
GTPase-Activating Proteins
Hela Cells
Humans
Mutation
Protein Binding
Protein Conformation
Protein Structure, Tertiary
Protein Transport
rac GTP-Binding Proteins
Type C Phospholipases
Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin
topic_facet Amines
Amino acids
Binding energy
Binding sites
Bioactivity
Biochemistry
Cell membranes
Cytology
Esterification
Esters
Gallium alloys
Glycerol
Growth (materials)
Ligands
Organic acids
Organic compounds
Peptides
Pneumatic control equipment
Activating proteins
C1 domains
Cell functions
Cell migrations
Diacylglycerol
Epidermal growth factors
In vitro
Inactive conformations
Ligand bindings
Lipid second messengers
Membrane associations
Modeling analysis
Neuritogenesis
Phorbol esters
Phospholipase
Plasma membranes
Protein kinases
Terminal regions
Chemical activation
chimerin
chimerin alpha 2
epidermal growth factor
guanosine triphosphatase activating protein
phorbol 13 acetate 12 myristate
Rac protein
unclassified drug
article
binding site
cell membrane
human
human cell
priority journal
protein analysis
protein domain
protein function
protein localization
Animals
Cercopithecus aethiops
Chimerin 1
COS Cells
Epidermal Growth Factor
GTPase-Activating Proteins
Hela Cells
Humans
Mutation
Protein Binding
Protein Conformation
Protein Structure, Tertiary
Protein Transport
rac GTP-Binding Proteins
Type C Phospholipases
description Chimaerins are a family of GTPase activating proteins (GAPs) for the small G-protein Rac that have gained recent attention due to their important roles in development, cancer, neuritogenesis, and T-cell function. Like protein kinase C isozymes, chimaerins possess a C1 domain capable of binding phorbol esters and the lipid second messenger diacylglycerol (DAG) in vitro. Here we identified an autoinhibitory mechanism in α2-chimaerin that restricts access of phorbol esters and DAG, thereby limiting its activation. Although phorbol 12-myristate 13-acetate (PMA) caused limited translocation of wild-type α2-chimaerin to the plasma membrane, deletion of either N- or C-terminal regions greatly sensitize α2-chimaerin for intracellular redistribution and activation. Based on modeling analysis that revealed an occlusion of the ligand binding site in the α2-chimaerin C1 domain, we identified key amino acids that stabilize the inactive conformation. Mutation of these sites renders α2-chimaerin hypersensitive to C1 ligands, as reflected by its enhanced ability to translocate in response to PMA and to inhibit Rac activity and cell migration. Notably, in contrast to PMA, epidermal growth factor promotes full translocation of α2-chimaerin in a phospholipase C-dependent manner, but not of a C1 domain mutant with reduced affinity for DAG (P216A-α2- chimaerin). Therefore, DAG generation and binding to the C1 domain are required but not sufficient for epidermal growth factor-induced α2-chimaerin membrane association. Our studies suggest a role for DAG in anchoring rather than activation of α2-chimaerin. Like other DAG/phorbol ester receptors, including protein kinase C isozymes, α2-chimaerin is subject to autoinhibition by intramolecular contacts, suggesting a highly regulated mechanism for the activation of this Rac-GAP. © 2008 by The American Society for Biochemistry and Molecular Biology, Inc.
title Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin
title_short Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin
title_full Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin
title_fullStr Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin
title_full_unstemmed Identification of an autoinhibitory mechanism that restricts C1 domain-mediated activation of the Rac-GAP α2-chimaerin
title_sort identification of an autoinhibitory mechanism that restricts c1 domain-mediated activation of the rac-gap α2-chimaerin
publishDate 2008
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v283_n50_p35247_ColonGonzalez
http://hdl.handle.net/20.500.12110/paper_00219258_v283_n50_p35247_ColonGonzalez
_version_ 1768545080330682368