Human Tim8a, Tim8b and Tim13 are auxiliary assembly factors of mature Complex IV.
EMBO Rep
; 24(8): e56430, 2023 08 03.
Article
en En
| MEDLINE
| ID: mdl-37272231
ABSTRACT
Human Tim8a and Tim8b are paralogous intermembrane space proteins of the small TIM chaperone family. Yeast small TIMs function in the trafficking of proteins to the outer and inner mitochondrial membranes. This putative import function for hTim8a and hTim8b has been challenged in human models, but their precise molecular function(s) remains undefined. Likewise, the necessity for human cells to encode two Tim8 proteins and whether any potential redundancy exists is unclear. We demonstrate that hTim8a and hTim8b function in the assembly of cytochrome c oxidase (Complex IV). Using affinity enrichment mass spectrometry, we define the interaction network of hTim8a, hTim8b and hTim13, identifying subunits and assembly factors of the Complex IV COX2 module. hTim8-deficient cells have a COX2 and COX3 module defect and exhibit an accumulation of the Complex IV S2 subcomplex. These data suggest that hTim8a and hTim8b function in assembly of Complex IV via interactions with intermediate-assembly subcomplexes. We propose that hTim8-hTim13 complexes are auxiliary assembly factors involved in the formation of the Complex IV S3 subcomplex during assembly of mature Complex IV.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Saccharomyces cerevisiae
/
Proteínas de Transporte de Membrana Mitocondrial
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
EMBO Rep
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2023
Tipo del documento:
Article
País de afiliación:
Australia