The cytochrome b carboxyl terminal region is necessary for mitochondrial complex III assembly
Por:
Flores-Mireles, Daniel, Camacho-Villasana, Yolanda, Lutikurti, Madhurya, Garcia-Gurrerio, Aldo E., Lozano-Rosas, Guadalupe, Chagoya, Victoria, Gutierrez-Cirlos, Emma Berta, Brandt, Ulrich, Cabrera-Orefice, Alfredo, Perez-Martinez, Xochitl
Publicada:
1 ene 2023
Resumen:
Mitochondrial bc1 complex from yeast has 10 subunits, but only cytochrome b (Cytb) subunit is encoded in the mitochondrial genome. Cytb has eight transmembrane helices containing two hemes b for electron transfer. Cbp3 and Cbp6 assist Cytb synthesis, and together with Cbp4 induce Cytb hemylation. Subunits Qcr7/Qcr8 participate in the first steps of assembly, and lack of Qcr7 reduces Cytb synthesis through an assembly-feedback mechanism involving Cbp3/Cbp6. Because Qcr7 resides near the Cytb carboxyl region, we wondered whether this region is important for Cytb synthesis/assembly. Although deletion of the Cytb C-region did not abrogate Cytb synthesis, the assembly-feedback regulation was lost, so Cytb synthesis was normal even if Qcr7 was missing. Mutants lacking the Cytb C-terminus were non-respiratory because of the absence of fully assembled bc1 complex. By performing complexome profiling, we showed the existence of aberrant early-stage subassemblies in the mutant. In this work, we demonstrate that the C-terminal region of Cytb is critical for regulation of Cytb synthesis and bc1 complex assembly. © 2023 Flores-Mireles et al.
Filiaciones:
https://ror.org/01tmp8f25 Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de MéxicoMéxico City, Mexico
https://ror.org/01yb10j39 Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
Department of Medicine and Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, United States
https://ror.org/01tmp8f25 Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de MéxicoMéxico City, Mexico
Laboratorio de Bioquímica y Bioenergética, UBIMED, FES Iztacala, UNAMMéxico City, Mexico
Univ Nacl Autonoma Mexico, Dept Genet Mol, Inst Fisiologia Celular, Mexico City, Mexico
Radboud Univ Nijmegen, Radboud Inst Mol Life Sci, Med Ctr, Nijmegen, Netherlands
Univ Utah, Dept Med & Biochem, Sch Med, Salt Lake City, UT USA
Univ Nacl Autonoma Mexico, Dept Biol Celular & Desarrollo, Inst Fisiol Celular, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Lab Bioquim & Bioenerget, UBIMED, FES Iztacala, Mexico City, Mexico
gold, Green Submitted, All Open Access, Gold
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