Assembly factors monitor sequential hemylation of cytochrome b to regulate mitochondria! translation
2014 (English)In: Journal of Cell Biology, ISSN 0021-9525, E-ISSN 1540-8140, Vol. 205, no 4, 511-524 p.Article in journal (Refereed) Published
Mitochondrial respiratory chain complexes convert chemical energy into a membrane potential by connecting electron transport with charge separation. Electron transport relies on redox cofactors that occupy strategic positions in the complexes. How these redox cofactors are assembled into the complexes is not known. Cytochrome b, a central catalytic subunit of complex III, contains two henne bs. Here, we unravel the sequence of events in the mitochondrial inner membrane by which cytochrome b is hemylated. Heme incorporation occurs in a strict sequential process that involves interactions of the newly synthesized cytochrome b with assembly factors and structural complex III subunits. These interactions are functionally connected to cofactor acquisition that triggers the progression of cytochrome b through successive assembly intermediates. Failure to hemylate cytochrome b sequesters the Cbp3-Cbp6 complex in early assembly intermediates, thereby causing a reduction in cytochrome b synthesis via a feedback loop that senses hemylation of cytochrome b.
Place, publisher, year, edition, pages
2014. Vol. 205, no 4, 511-524 p.
IdentifiersURN: urn:nbn:se:su:diva-105918DOI: 10.1083/jcb.201401009ISI: 000336639000008OAI: oai:DiVA.org:su-105918DiVA: diva2:733258
FunderSwedish Research CouncilCarl Tryggers foundation Knut and Alice Wallenberg FoundationNIH (National Institute of Health), GM101386