Guanine nucleotide exchange factor αPIX leads to activation of the Rac 1 GTPase/glycogen phosphorylase pathway in interleukin (IL)-2-stimulated T cells

Francisco Llavero, Bakarne Urzelai, Nerea Osinalde, Patricia Gálvez, Hadriano M Lacerda, Luis A Parada, José L Zugaza

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Resumé

Recently, we have reported that the active form of Rac 1 GTPase binds to the glycogen phosphorylase muscle isoform (PYGM) and modulates its enzymatic activity leading to T cell proliferation. In the lymphoid system, Rac 1 and in general other small GTPases of the Rho family participate in the signaling cascades that are activated after engagement of the T cell antigen receptor. However, little is known about the IL-2-dependent Rac 1 activator molecules. For the first time, a signaling pathway leading to the activation of Rac 1/PYGM in response to IL-2-stimulated T cell proliferation is described. More specifically, αPIX, a known guanine nucleotide exchange factor for the small GTPases of the Rho family, preferentially Rac 1, mediates PYGM activation in Kit 225 T cells stimulated with IL-2. Using directed mutagenesis, phosphorylation of αPIX Rho-GEF serines 225 and 488 is required for activation of the Rac 1/PYGM pathway. IL-2-stimulated serine phosphorylation was corroborated in Kit 225 T cells cultures. A parallel pharmacological and genetic approach identified PKCθ as the serine/threonine kinase responsible for αPIX serine phosphorylation. The phosphorylated state of αPIX was required to activate first Rac 1 and subsequently PYGM. These results demonstrate that the IL-2 receptor activation, among other early events, leads to activation of PKCθ. To activate Rac 1 and consequently PYGM, PKCθ phosphorylates αPIX in T cells. The biological significance of this PKCθ/αPIX/Rac 1 GTPase/PYGM signaling pathway seems to be the control of different cellular responses such as migration and proliferation.

OriginalsprogEngelsk
TidsskriftJournal of Biological Chemistry
Vol/bind290
Udgave nummer14
Sider (fra-til)9171-9182
ISSN0021-9258
DOI
StatusUdgivet - 2015

Fingeraftryk

Guanine Nucleotide Exchange Factors
Glycogen Phosphorylase
T-cells
GTP Phosphohydrolases
Interleukin-2
Chemical activation
Phosphorylation
Serine
Monomeric GTP-Binding Proteins
Cell proliferation
Cell Proliferation
Mutagenesis
Interleukin-2 Receptors
Protein-Serine-Threonine Kinases
T-Cell Antigen Receptor
Cell culture
Muscle
Protein Isoforms
Muscles
Molecules

Citer dette

Llavero, Francisco ; Urzelai, Bakarne ; Osinalde, Nerea ; Gálvez, Patricia ; Lacerda, Hadriano M ; Parada, Luis A ; Zugaza, José L. / Guanine nucleotide exchange factor αPIX leads to activation of the Rac 1 GTPase/glycogen phosphorylase pathway in interleukin (IL)-2-stimulated T cells. I: Journal of Biological Chemistry. 2015 ; Bind 290, Nr. 14. s. 9171-9182.
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title = "Guanine nucleotide exchange factor αPIX leads to activation of the Rac 1 GTPase/glycogen phosphorylase pathway in interleukin (IL)-2-stimulated T cells",
abstract = "Recently, we have reported that the active form of Rac 1 GTPase binds to the glycogen phosphorylase muscle isoform (PYGM) and modulates its enzymatic activity leading to T cell proliferation. In the lymphoid system, Rac 1 and in general other small GTPases of the Rho family participate in the signaling cascades that are activated after engagement of the T cell antigen receptor. However, little is known about the IL-2-dependent Rac 1 activator molecules. For the first time, a signaling pathway leading to the activation of Rac 1/PYGM in response to IL-2-stimulated T cell proliferation is described. More specifically, αPIX, a known guanine nucleotide exchange factor for the small GTPases of the Rho family, preferentially Rac 1, mediates PYGM activation in Kit 225 T cells stimulated with IL-2. Using directed mutagenesis, phosphorylation of αPIX Rho-GEF serines 225 and 488 is required for activation of the Rac 1/PYGM pathway. IL-2-stimulated serine phosphorylation was corroborated in Kit 225 T cells cultures. A parallel pharmacological and genetic approach identified PKCθ as the serine/threonine kinase responsible for αPIX serine phosphorylation. The phosphorylated state of αPIX was required to activate first Rac 1 and subsequently PYGM. These results demonstrate that the IL-2 receptor activation, among other early events, leads to activation of PKCθ. To activate Rac 1 and consequently PYGM, PKCθ phosphorylates αPIX in T cells. The biological significance of this PKCθ/αPIX/Rac 1 GTPase/PYGM signaling pathway seems to be the control of different cellular responses such as migration and proliferation.",
keywords = "Base Sequence, Cell Line, Cell Proliferation, Chemotaxis, Leukocyte, DNA Primers, Enzyme Activation, Glycogen Phosphorylase, Humans, Interleukin-12, Polymerase Chain Reaction, Rho Guanine Nucleotide Exchange Factors, T-Lymphocytes, rac1 GTP-Binding Protein",
author = "Francisco Llavero and Bakarne Urzelai and Nerea Osinalde and Patricia G{\'a}lvez and Lacerda, {Hadriano M} and Parada, {Luis A} and Zugaza, {Jos{\'e} L}",
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doi = "10.1074/jbc.M114.608414",
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journal = "Journal of Biological Chemistry",
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Guanine nucleotide exchange factor αPIX leads to activation of the Rac 1 GTPase/glycogen phosphorylase pathway in interleukin (IL)-2-stimulated T cells. / Llavero, Francisco; Urzelai, Bakarne; Osinalde, Nerea; Gálvez, Patricia; Lacerda, Hadriano M; Parada, Luis A; Zugaza, José L.

I: Journal of Biological Chemistry, Bind 290, Nr. 14, 2015, s. 9171-9182.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Guanine nucleotide exchange factor αPIX leads to activation of the Rac 1 GTPase/glycogen phosphorylase pathway in interleukin (IL)-2-stimulated T cells

AU - Llavero, Francisco

AU - Urzelai, Bakarne

AU - Osinalde, Nerea

AU - Gálvez, Patricia

AU - Lacerda, Hadriano M

AU - Parada, Luis A

AU - Zugaza, José L

N1 - © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

PY - 2015

Y1 - 2015

N2 - Recently, we have reported that the active form of Rac 1 GTPase binds to the glycogen phosphorylase muscle isoform (PYGM) and modulates its enzymatic activity leading to T cell proliferation. In the lymphoid system, Rac 1 and in general other small GTPases of the Rho family participate in the signaling cascades that are activated after engagement of the T cell antigen receptor. However, little is known about the IL-2-dependent Rac 1 activator molecules. For the first time, a signaling pathway leading to the activation of Rac 1/PYGM in response to IL-2-stimulated T cell proliferation is described. More specifically, αPIX, a known guanine nucleotide exchange factor for the small GTPases of the Rho family, preferentially Rac 1, mediates PYGM activation in Kit 225 T cells stimulated with IL-2. Using directed mutagenesis, phosphorylation of αPIX Rho-GEF serines 225 and 488 is required for activation of the Rac 1/PYGM pathway. IL-2-stimulated serine phosphorylation was corroborated in Kit 225 T cells cultures. A parallel pharmacological and genetic approach identified PKCθ as the serine/threonine kinase responsible for αPIX serine phosphorylation. The phosphorylated state of αPIX was required to activate first Rac 1 and subsequently PYGM. These results demonstrate that the IL-2 receptor activation, among other early events, leads to activation of PKCθ. To activate Rac 1 and consequently PYGM, PKCθ phosphorylates αPIX in T cells. The biological significance of this PKCθ/αPIX/Rac 1 GTPase/PYGM signaling pathway seems to be the control of different cellular responses such as migration and proliferation.

AB - Recently, we have reported that the active form of Rac 1 GTPase binds to the glycogen phosphorylase muscle isoform (PYGM) and modulates its enzymatic activity leading to T cell proliferation. In the lymphoid system, Rac 1 and in general other small GTPases of the Rho family participate in the signaling cascades that are activated after engagement of the T cell antigen receptor. However, little is known about the IL-2-dependent Rac 1 activator molecules. For the first time, a signaling pathway leading to the activation of Rac 1/PYGM in response to IL-2-stimulated T cell proliferation is described. More specifically, αPIX, a known guanine nucleotide exchange factor for the small GTPases of the Rho family, preferentially Rac 1, mediates PYGM activation in Kit 225 T cells stimulated with IL-2. Using directed mutagenesis, phosphorylation of αPIX Rho-GEF serines 225 and 488 is required for activation of the Rac 1/PYGM pathway. IL-2-stimulated serine phosphorylation was corroborated in Kit 225 T cells cultures. A parallel pharmacological and genetic approach identified PKCθ as the serine/threonine kinase responsible for αPIX serine phosphorylation. The phosphorylated state of αPIX was required to activate first Rac 1 and subsequently PYGM. These results demonstrate that the IL-2 receptor activation, among other early events, leads to activation of PKCθ. To activate Rac 1 and consequently PYGM, PKCθ phosphorylates αPIX in T cells. The biological significance of this PKCθ/αPIX/Rac 1 GTPase/PYGM signaling pathway seems to be the control of different cellular responses such as migration and proliferation.

KW - Base Sequence

KW - Cell Line

KW - Cell Proliferation

KW - Chemotaxis, Leukocyte

KW - DNA Primers

KW - Enzyme Activation

KW - Glycogen Phosphorylase

KW - Humans

KW - Interleukin-12

KW - Polymerase Chain Reaction

KW - Rho Guanine Nucleotide Exchange Factors

KW - T-Lymphocytes

KW - rac1 GTP-Binding Protein

U2 - 10.1074/jbc.M114.608414

DO - 10.1074/jbc.M114.608414

M3 - Journal article

VL - 290

SP - 9171

EP - 9182

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 14

ER -