Respiratory chain complexes in mitochondria are assembled from subunits derived from two genetic systems. For example, the bc(1) complex consists of nine nuclear encoded subunits and the mitochondrially encoded subunit cytochrome b. We recently showed that the Cbp3-Cbp6 complex has a dual function for biogenesis of cytochrome b: it is both required for efficient synthesis of cytochrome b and for protection of the newly synthesized protein from proteolysis. Here, we report that Cbp3-Cbp6 also coordinates cytochrome b synthesis with bc(1) complex assembly. We show that newly synthesized cytochrome b assembled through a series of four assembly intermediates. Blocking assembly at early and intermediate steps resulted in sequestration of Cbp3-Cbp6 in a cytochrome b-containing complex, thereby making Cbp3-Cbp6 unavailable for cytochrome b synthesis and thus reducing overall cytochrome b levels. This feedback loop regulates protein synthesis at the inner mitochondrial membrane by directly monitoring the efficiency of bc(1) complex assembly.
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http://dx.doi.org/10.1083/jcb.201206040 | DOI Listing |
Int J Mol Sci
December 2024
Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio n.42, 40126 Bologna, Italy.
Disaccharide trehalose has been proven in many cases to be particularly effective in preserving the functional and structural integrity of biological macromolecules. In this work, we studied its effect on the electron transfer reactions that occur in the chromatophores of the photosynthetic bacterium . In the presence of a high concentration of trehalose, following the activation of the photochemistry by flashes of light, a slowdown of the electrogenic reactions related to the activity of the photosynthetic reaction center and cytochtome (cyt) complexes is observable.
View Article and Find Full Text PDFBiomolecules
November 2024
Department of Biology, Washington University, St. Louis, MO 63146, USA.
Mitochondrial holocytochrome c synthase (HCCS) is an essential protein in assembling cytochrome c (cyt c) of the electron transport system. HCCS binds heme and covalently attaches the two vinyls of heme to two cysteine thiols of the cyt c CXXCH motif. Human HCCS recognizes both cyt c and cytochrome c of complex III (cytochrome bc).
View Article and Find Full Text PDFEur J Med Chem
December 2024
School of Pharmacy and Food Engineering, Wuyi University, 529020, Jiangmen, China; Department of Chemistry, University of Liverpool, L69 7ZD, Liverpool, UK. Electronic address:
Aryl quinolone derivatives can target the cytochrome bc complex of Plasmodium falciparum, exhibiting excellent in vitro and in vivo antimalarial activity. However, their clinical development has been hindered due to their poor aqueous solubility profiles. In this study, a series of bioisosteres containing saturated heterocycles fused to a 4-pyridone ring were designed to replace the inherently poorly soluble quinolone core in antimalarial quinolones with the aim to reduce π-π stacking interactions in the crystal packing solid state, and a synthetic route was developed to prepare these alternative core derivatives.
View Article and Find Full Text PDFFront Plant Sci
November 2024
Key Laboratory of Biohazard Monitoring, Green Prevention and Control for Artificial Grassland, Ministry of Agriculture and Rural Affairs, Institute of Grassland Research of Chinese Academy of Agricultural Sciences, Hohhot, China.
J Med Chem
December 2024
Instituto Nacional de Ciência e Tecnologia em Tuberculose, Centro de Pesquisas em Biologia Molecular e Funcional, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 90616-900, Brazil.
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