BolA-like protein 2
cytoplasm
BOLA1 is an aerobic protein that prevents mitochondrial morphology changes induced by glutathione depletion.
<h4>Aims</h4>The BolA protein family is widespread among eukaryotes and bacteria. In Escherichia coli, BolA causes a spherical cell shape and is overexpressed during oxidative stress. Here we aim to elucidate the possible role of its human homolog BOLA1 in mitochondrial morphology and thiol redox potential regulation.<h4>Results</h4>We show that BOLA1 is a mitochondrial protein that counterbalances the effect of L-buthionine-(S,R)-sulfoximine (BSO)-induced glutathione (GSH) depletion on the mitochondrial thiol redox potential. Furthermore, overexpression of BOLA1 nullifies the effect of BSO and S-nitrosocysteine on mitochondrial morphology. Conversely, knockdown of the BOLA1 gene increases the oxidation of mitochondrial thiol groups. Supporting a role of BOLA1 in controlling the mitochondrial thiol redox potential is that BOLA1 orthologs only occur in aerobic eukaryotes. A measured interaction of BOLA1 with the mitochondrial monothiol glutaredoxin GLRX5 provides hints for potential mechanisms behind BOLA1's effect on mitochondrial redox potential. Nevertheless, we have no direct evidence for a role of GLRX5 in BOLA1's function.<h4>Innovation</h4>We implicate a new protein, BOLA1, in the regulation of the mitochondrial thiol redox potential.<h4>Conclusion</h4>BOLA1 is an aerobic, mitochondrial protein that prevents mitochondrial morphology aberrations induced by GSH depletion and reduces the associated oxidative shift of the mitochondrial thiol redox potential.