A Novel Potassium Channel in Lymphocyte Mitochondria

The margatoxin-sensitive Kv1.3 is the major potassium channel in the plasma membrane of T lymphocytes. Electron microscopy, patch clamp, and immunological studies identified the potassium channel Kv1.3, thought to be localized exclusively in the cell membrane, in the inner mitochondrial membrane of...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2005-04, Vol.280 (13), p.12790-12798
Main Authors: Szabò, Ildikò, Bock, Jurgen, Jekle, Andreas, Soddemann, Matthias, Adams, Constantin, Lang, Florian, Zoratti, Mario, Gulbins, Erich
Format: Article
Language:English
Subjects:
Blotting, Western
Cell Line
Cell Membrane - metabolism
Flow Cytometry
Humans
Intracellular Membranes - metabolism
Jurkat Cells
Kv1.3 Potassium Channel
Lymphocytes - metabolism
Membrane Potentials
Microscopy, Electron
Microscopy, Electron, Transmission
Mitochondria - metabolism
Neurotoxins - pharmacology
Patch-Clamp Techniques
Potassium Channels - chemistry
Potassium Channels, Voltage-Gated - metabolism
Scorpion Venoms
T-Lymphocytes - immunology
Transfection
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The margatoxin-sensitive Kv1.3 is the major potassium channel in the plasma membrane of T lymphocytes. Electron microscopy, patch clamp, and immunological studies identified the potassium channel Kv1.3, thought to be localized exclusively in the cell membrane, in the inner mitochondrial membrane of T lymphocytes. Patch clamp of mitoplasts and mitochondrial membrane potential measurements disclose the functional expression of a mitochondrial margatoxin-sensitive potassium channel. To identify unambiguously the mitochondrial localization of Kv1.3, we employed a genetic model and stably transfected CTLL-2 cells, which are genetically deficient for this channel, with Kv1.3. Mitochondria isolated from Kv1.3-reconstituted CTLL-2 expressed the channel protein and displayed an activity, which was identical to that observed in Jurkat mitochondria, whereas mitochondria of mock-transfected cells lacked a channel with the characteristics of Kv1.3. Our data provide the first molecular identification of a mitochondrial potassium conductance.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M413548200