2010 Fiscal Year Final Research Report
Regulation of K-Cl transporter and modal shift of GABA response in development and recovery.
| Project Area | Molecular interaction and modal shift of cellular sensors |
|---|
| Project/Area Number |
18077009
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
|
| Allocation Type | Single-year Grants |
|---|
| Review Section |
Biological Sciences
|
|---|
| Research Institution | National Institute for Physiological Sciences |
|---|
Principal Investigator |
NABEKURA Junichi National Institute for Physiological Sciences, 発達生理学研究系, 教授 (50237583)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MAEJIMA Takashi 生理学研究所, 発達生理学研究系, 助教 (70399319)
WATANABE Miho 生理学研究所, 発達生理学研究系, 特任助教 (10399321)
TAKATSURU Yusuke 生理学研究所, 発達生理学研究系, 特別協力研究員 (30446265)
|
|---|
| Co-Investigator(Renkei-kenkyūsha) |
WATANABE Miho 生理学研究所, 発達生理学研究系, 特任助教 (10399321)
|
|---|
| Project Period (FY) |
2006 – 2010
|
| Keywords | KCC2 / GABA / モーダルシフト |
|---|
| Research Abstract |
The neuronal K(+)-Cl(-) cotransporter (KCC2) is a membrane transport protein that extrudes Cl(-) from neurons and helps maintain low intracellular [Cl(-)] and hyperpolarizing GABAergic synaptic potentials. Depolarizing gamma-aminobutyric acid (GABA) responses in neonatal neurons and following various forms of neuronal injury are associated with reduced levels of KCC2 expression. Mutation to the putative tyrosine phosphorylation site within the long intracellular carboxyl terminus of KCC2(Y1087D) or application of the tyrosine kinase inhibitor genistein shifted the GABA reversal potential (E(GABA)) to more depolarized values, indicating reduced KCC2 function. This was associated with a change in the expression pattern of KCC2 from a punctate distribution to a more uniform distribution, suggesting that functional tyrosine-phosphorylated KCC2 forms clusters in restricted membrane domains. A tyrosine phosphatase inhibitor increased the proportion of KCC2 associated with lipid rafts membrane domains. These results indicate that direct tyrosine phosphorylation of KCC2 results in membrane clusters and functional transport activity. Oxidative stress resulted in a rapid dephosphorylation of KCC2 that preceded the decreases in KCC2 protein or mRNA expression. Dephosphorylation of KCC2 is correlated with a reduction of transport activity and a decrease in [Cl-]i, as well as a reduction in KCC2 surface expression. Manipulation of KCC2 tyrosine phosphorylation resulted in altered neuronal viability in response to in vitro oxidative stress. We propose that neuronal stress induces a rapid loss of tyrosine phosphorylation of KCC2 that results in translocation of the protein and functional loss of transport activity.
|
Research Products
(34 results)
-
-
[Journal Article] GABA(A) receptor subunit alteration-dependent diazepam insensitivity in the cerebellum of phospholipase C-related inactive protein knockout mice.2010
Author(s)
Mizokami A, Tanaka H, Ishibashi H, Umebayashi H, Fukami K, Takenawa T, Nakayama KI, Yokoyama T, Nabekura J, Kanematsu T, Hirata M.
-
Journal Title
Journal of Neurochemistry 114
Pages: 302-310
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
[Journal Article] Phosholipase C-Related Inactive Protein is involved in Trafficking of gamma2 Subunit Containing GABAA Receptor to Cell Surface.2007
Author(s)
Mizokami A, Kanematsu Ti, Ishibashi H, Yamaguchi T, Tanida I, Takenaka K, Nakayama K, Fukami K, Takenawa T, Kominami E, Moss S, Yamamoto T, Nabekura J, Hirata H.
-
Journal Title
Journal of Neuroscience 27
Pages: 1692-1701
-
[Journal Article] Early changes in KCC2 phosphorylation in response to neuronal stress results in functional downregulation.2007
Author(s)
Wake H, Watanabe M, Moorhouse AJ, Kanematsu T, Horibe S, Matsukawa N, Asai K,, Ojika K, Hirata M, Nabekura J.
-
Journal Title
Journal of Neuroscience 27
Pages: 1642-1650
-
-
[Journal Article] Modulation of GABAA Receptor Phosphorylation and Membrane Trafficking by Phospholipase C-related Inactive Protein/Protein Phosphatase 1 and 2A Signaling Complex Underlying Brain-derived Neurotrophic Factor-dependent Regulation of GABAergic Inhibition.2006
Author(s)
Kanematsu T, Yasunaga A, Mizoguchi Y, Kuratani A, Kittler JT, Jovanovic JN, Takenaka K, Nakayama KI, Fukami K, Takenawa T, Moss SJ, Nabekura J, Hirata M
-
Journal Title
Journal of Biological Chemistry 281
Pages: 22180-22189
-
-
-
-
-
-
-
-
-
-
-
-
-
