Brain‐type creatine kinase activates neuron‐specific K+‐Cl– co‐transporter KCC2
- 29 November 2005
- journal article
- Published by Wiley in Journal of Neurochemistry
- Vol. 96 (2) , 598-608
- https://doi.org/10.1111/j.1471-4159.2005.03560.x
Abstract
GABA, a major inhibitory neurotransmitter in the adult CNS, is excitatory at early developmental stages as a result of the elevated intracellular Cl- concentration ([Cl-]i). This functional switch is primarily attributable to the K+-Cl- co-transporter KCC2, the expression of which is developmentally regulated in neurons. Previously, we reported that KCC2 interacts with brain-type creatine kinase (CKB). To elucidate the functional significance of this interaction, HEK293 cells were transfected with KCC2 and glycine receptor alpha2 subunit, and gramicidin-perforated patch-clamp recordings were performed to measure the glycine reversal potential (Egly), giving an estimate of [Cl-]i. KCC2-expressing cells displayed the expected changes in Egly following alterations in the extracellular K+ concentration ([K+]o) or administration of an inhibitor of KCCs, suggesting that the KCC2 function was being properly assessed. When added into KCC2-expressing cells, dominant-negative CKB induced a depolarizing shift in Egly and reduced the hyperpolarizing shift in Egly seen in response to a lowering of [K+]o compared with wild-type CKB. Moreover, 2,4-dinitrofluorobenzene (DNFB), an inhibitor of CKs, shifted Egly in the depolarizing direction. In primary cortical neurons expressing CKB, the GABA reversal potential was also shifted in the depolarizing direction by DNFB. Our findings suggest that, in the cellular micro-environment, CKB activates the KCC2 function.Keywords
This publication has 53 references indexed in Scilit:
- Characterization of newly cloned variant of rat glycine receptor α1 subunitBiochemical and Biophysical Research Communications, 2005
- Malfunction of Respiratory-Related Neuronal Activity in Na+, K+-ATPase α2 Subunit-Deficient Mice Is Attributable to Abnormal Cl-Homeostasis in Brainstem NeuronsJournal of Neuroscience, 2004
- Interaction of neuron‐specific K+‐Cl− cotransporter, KCC2, with brain‐type creatine kinaseFEBS Letters, 2004
- Trans-synaptic shift in anion gradient in spinal lamina I neurons as a mechanism of neuropathic painNature, 2003
- Is there more to gaba than synaptic inhibition?Nature Reviews Neuroscience, 2002
- Human and Murine Phenotypes Associated with Defects in Cation-Chloride CotransportAnnual Review of Physiology, 2002
- Autophosphorylation of creatine kinase: characterization and identification of a specifically phosphorylated peptideBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1995
- Determination of the catalytic site of creatine kinase by site-directed mutagenesisBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1994
- Cloning of a glycine receptor subtype expressed in rat brain and spinal cord during a specific period of neuronal developmentFEBS Letters, 1991
- A membrane‐associated creatine kinase (EC 2.7.3.2) identified as an acidic species of the non‐receptor, peripheral v‐proteins in Torpedo acetylcholine receptor membranesFEBS Letters, 1983