K+/H+ exchange

Contributor: Saverio Marchi
{"name":"K+\/H+ exchange","theorem":{"head":{"_type":"conjunction","components":[{"_type":"molecule","name":"K+","position":4},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":1}]},"body":{"_type":"conjunction","components":[{"_type":"molecule","name":"K+","position":1},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":4}]}},"steps":[{"head":{"_type":"interaction","position":0,"components":[{"_type":"molecule","name":"K+","position":1},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":4}]},"body":{"_type":"conjunction","components":[{"_type":"molecule","name":"K+","position":1},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":4}]}},{"head":{"_type":"interaction","position":0,"components":[{"_type":"molecule","name":"K+","position":4},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":1}]},"body":{"_type":"interaction","position":0,"components":[{"_type":"molecule","name":"K+","position":1},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":4}]}},{"head":{"_type":"conjunction","components":[{"_type":"molecule","name":"K+","position":4},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":1}]},"body":{"_type":"interaction","position":0,"components":[{"_type":"molecule","name":"K+","position":4},{"_type":"protein","name":"LETM1","position":2},{"_type":"molecule","name":"H+","position":1}]}}]}

Theorem

Information

The Leucine zipper-EF-hand-containing transmembrane protein1 (LETM1), located at the inner mitochondrial membrane, has been indicated to fuction as the K+/H+ antiporter, and LETM1-depleted mitochondria accumulate high K+ levels inside their matrix. Moreover, it has been proposed that the LETM1-dependent Ca2+ efflux is modulated by mitochondrial Na+ homeostasis.

 

References:

Nowikovsky K, Froschauer EM, Zsurka G, Samaj J, Reipert S, Kolisek M, Wiesenberger G, Schweyen RJ. The LETM1/YOL027 gene family encodes a factor of the mitochondrial K+ homeostasis with a potential role in the Wolf-Hirschhorn syndrome. J Biol Chem. 2004 Jul 16;279(29):30307-15. doi: 10.1074/jbc.M403607200. Epub 2004 May 11. PMID: 15138253.

De Marchi U, Santo-Domingo J, Castelbou C, Sekler I, Wiederkehr A, Demaurex N. NCLX protein, but not LETM1, mediates mitochondrial Ca2+ extrusion, thereby limiting Ca2+-induced NAD(P)H production and modulating matrix redox state. J Biol Chem. 2014 Jul 18;289(29):20377-85. doi: 10.1074/jbc.M113.540898. Epub 2014 Jun 4. PMID: 24898248.

Austin S, Tavakoli M, Pfeiffer C, Seifert J, Mattarei A, De Stefani D, Zoratti M, Nowikovsky K. LETM1-Mediated K+ and Na+
Homeostasis Regulates Mitochondrial Ca2+ Efflux. Front Physiol. 2017 Nov 17;8:839. doi: 10.3389/fphys.2017.00839. PMID: 29204122.

Mitochondrial processes

Demonstrative and biological steps

Dynamic view

Mito-location

Not Available/Not Relevant
    M
    Matrix
      IM
      Inner Membrane
        IMS
        Inter-Membrane Space
          OM
          Outer Membrane
            PMS
            Peri-Mitochondrial Space

              Dynamic mito-location