Related Experiment Video

Updated: Jul 15, 2026

F1FO ATPase Vesicle Preparation and Technique for Performing Patch Clamp Recordings of Submitochondrial Vesicle Membranes
08:21

F1FO ATPase Vesicle Preparation and Technique for Performing Patch Clamp Recordings of Submitochondrial Vesicle Membranes

Published on: May 4, 2013

ATP-sensitive potassium channel in mitochondria of the eukaryotic microorganism Acanthamoeba castellanii

Anna Kicinska1, Aleksandra Swida, Piotr Bednarczyk

  • 1Laboratory of Bioenergetics, Adam Mickiewicz University, 61-614 Poznan, Poland.

The Journal of Biological Chemistry
|April 14, 2007
PubMed

Insights

A potassium ion transport mechanism was found in Acanthamoeba castellanii mitochondria. This ATP-sensitive potassium channel influences mitochondrial bioenergetics and membrane potential, similar to mammalian mitochondria.

Area of Science:

  • Mitochondrial biology
  • Cellular bioenergetics
  • Ion transport mechanisms

Background:

  • Mitochondria play a crucial role in cellular energy production.
  • Potassium channels are vital for regulating mitochondrial function.
  • Lower eukaryotes offer unique models for studying fundamental cellular processes.

Purpose of the Study:

  • To investigate the presence and function of potassium ion transport in Acanthamoeba castellanii mitochondria.
  • To characterize the bioenergetic effects of potassium channel modulators on A. castellanii mitochondria.
  • To describe the electrophysiological properties of mitochondrial potassium channels in this organism.

Main Methods:

  • Isolated mitochondria from A. castellanii were used to study respiration and membrane potential.
  • Potassium channel openers (diazoxide, BMS-191095) and blockers (glibenclamide) were employed.
  • Electrophysiological recordings of reconstituted inner mitochondrial membrane channels in black lipid membranes were performed.

Main Results:

  • Potassium channel openers increased resting respiration by ~10% in A. castellanii mitochondria, dependent on potassium ions and reversed by glibenclamide.
  • Diazoxide and BMS-191095 caused mitochondrial membrane depolarization, restored by glibenclamide or ATP.
  • Reconstituted channels exhibited conductance, inhibition by ATP/Mg(2+) and glibenclamide, and activation by diazoxide.

Conclusions:

  • A potassium ion transport mechanism, likely an ATP-sensitive potassium channel, exists in the inner mitochondrial membrane of A. castellanii.
  • This channel shares functional similarities with mammalian mitochondrial ATP-sensitive potassium channels.
  • The findings contribute to understanding mitochondrial bioenergetics and ion transport in lower eukaryotes.

More Related Videos

Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays12:48

Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays

Published on: February 19, 2013

Visualization of ATP Synthase Dimers in Mitochondria by Electron Cryo-tomography10:39

Visualization of ATP Synthase Dimers in Mitochondria by Electron Cryo-tomography

Published on: September 14, 2014

Related Concept Videos

ATP Synthase: Mechanism01:48

ATP Synthase: Mechanism

In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
The ADP/ATP Carrier Protein01:42

The ADP/ATP Carrier Protein

ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational...
ATP Synthase: Structure01:18

ATP Synthase: Structure

ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
ATP Driven Pumps III: V-type Pumps01:30

ATP Driven Pumps III: V-type Pumps

V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
ATP Driven Pumps I: An Overview01:27

ATP Driven Pumps I: An Overview

ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
Energy to Drive Translocation01:37

Energy to Drive Translocation

Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...