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Published on: June 1, 2022
Extramitochondrial porin: facts and hypotheses
G Báthori1, I Parolini, I Szabó
1Department of Physiology, Semmelweis Medical University, Budapest, Hungary. bathory@puskin.sote.hu
Journal of Bioenergetics and Biomembranes
|January 5, 2002
Summary
New research confirms the presence of voltage-dependent anion channel (VDAC) porin in the plasma membrane of hematopoietic cells. This protein, typically found in mitochondria, may play a role in cellular transport and signaling.
Area of Science:
- Cell Biology
- Biochemistry
- Membrane Protein Research
Background:
- Mitochondrial porin, or voltage-dependent anion channel (VDAC), is primarily known as a pore-forming protein in the outer mitochondrial membrane.
- Previous reports of extramitochondrial VDAC localization were often met with skepticism due to insufficient evidence.
Purpose of the Study:
- To investigate and confirm the presence of VDAC in non-mitochondrial cellular compartments.
- To characterize the properties and localization of VDAC in the plasma membrane of hematopoietic cells.
Main Methods:
- Purification of plasma membrane porin from intact hematopoietic cells using NH-SS-biotin labeling and streptavidin affinity chromatography.
- Characterization of purified protein to compare its properties with mitochondrial VDAC.
- Patch-clamp electrophysiology on intact cells to observe channel activity.
Main Results:
- New data strongly indicate the presence of VDAC in the plasma membrane of hematopoietic cells, likely within caveolae or caveolae-like domains.
- Purified plasma membrane porin exhibited properties identical to mitochondrial VDAC.
- Patch-clamp recordings revealed a channel in intact cells with characteristics similar to isolated VDAC.
Conclusions:
- This study provides robust evidence for the extramitochondrial localization of VDAC in the plasma membrane.
- The findings suggest a potential identification of plasma membrane VDAC with the "maxi" chloride channel.
- Further research is warranted to explore the mechanisms of VDAC sorting and its functional roles in extramitochondrial membranes.
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