Cbp3 and Cbp6 are dispensable for synthesis regulation of cytochrome b in yeast mitochondria
Por:
Garcia-Guerrero, Aldo E., Camacho-Villasana, Yolanda, Zamudio-Ochoa, Angelica, Winge, Dennis R., Perez-Martinez, Xochitl
Publicada:
13 abr 2018
Resumen:
Cytochrome b (Cytb) is the only mitochondrial encoded subunit from the
bc(1) complex. Cbp3 and Cbp6 are chaperones necessary for translation of
the COB mRNA and Cytb hemylation. Here we demonstrate that their role in
translation is dispensable in some laboratory strains, whereas their
role in Cytb hemylation seems to be universally conserved. BY4742 yeast
requires Cbp3 and Cbp6 for efficient COB mRNA translation, whereas the
D273-10b strain synthesizes Cytb at wildtype levels in the absence of
Cbp3 and Cbp6. Steady-state levels of Cytb are close to wildtype in
mutant D273-10b cells, and Cytb forms non-functional, supercomplex-like
species with cytochrome c oxidase, in which at least core 1, cytochrome
c(1), and Rieske iron-sulfur subunits are present. We demonstrated that
Cbp3 interacts with the mitochondrial ribosome and with the COB mRNA in
both BY4742 and D273-10b strains. The polymorphism( s) causing the
differential function of Cbp3, Cbp6, and the assembly feedback
regulation of Cytb synthesis is of nuclear origin rather than
mitochondrial, and Smt1, a COB mRNA-binding protein, does not seem to be
involved in the observed differential phenotype. Our results indicate
that the essential role of Cbp3 and Cbp6 is to assist Cytb hemylation
and demonstrate that in the absence of heme b, Cytb can form
non-functional supercomplexes with cytochrome c oxidase. Our
observations support that an additional protein or proteins are involved
in Cytb synthesis in some yeast strains.
Filiaciones:
Garcia-Guerrero, Aldo E.:
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n Ciudad Universitaria, Coyoacán, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Dept Genet Mol, Circuito Exterior S-N Ciudad Univ, Mexico City 04510, DF, Mexico
Camacho-Villasana, Yolanda:
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n Ciudad Universitaria, Coyoacán, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Dept Genet Mol, Circuito Exterior S-N Ciudad Univ, Mexico City 04510, DF, Mexico
Zamudio-Ochoa, Angelica:
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n Ciudad Universitaria, Coyoacán, Mexico City, Mexico
Dept. of Cell Biology, School of Osteopathic Medicine, Rowan University, 2 Medical Center Dr., Stratford, NJ, United States
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Dept Genet Mol, Circuito Exterior S-N Ciudad Univ, Mexico City 04510, DF, Mexico
Rowan Univ, Sch Osteopath Med, Dept Cell Biol, 2 Med Ctr Dr, Stratford, NJ 08084 USA
Winge, Dennis R.:
Department of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake, UT, United States
Univ Utah, Dept Med & Biochem, Hlth Sci Ctr, Salt Lake City, UT 84132 USA
Perez-Martinez, Xochitl:
Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n Ciudad Universitaria, Coyoacán, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Fisiol Celular, Dept Genet Mol, Circuito Exterior S-N Ciudad Univ, Mexico City 04510, DF, Mexico
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