Redefining the roles of mitochondrial DNA-encoded subunits in respiratory Complex I assembly

Rasika Vartak, Janice Deng, Hezhi Fang, Yidong Bai

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Respiratory Complex I deficiency is implicated in numerous degenerative and metabolic diseases. In particular, mutations in several mitochondrial DNA (mtDNA)-encoded Complex I subunits including ND4, ND5 and ND6 have been identified in several neurological diseases. We previously demonstrated that these subunits played essential roles in Complex I assembly which in turn affected mitochondrial function. Here, we carried out a comprehensive study of the Complex I assembly pathway. We identified a new Complex I intermediate containing both membrane and matrix arms at an early assembly stage. We find that lack of the ND6 subunit does not hinder membrane arm formation; instead it recruits ND1 and ND5 enters the intermediate. While ND4 is important for the formation of the newly identified intermediate, the addition of ND5 stabilizes the complex and is required for the critical transition from Complex I to supercomplex assembly. As a result, the Complex I assembly pathway has been redefined in this study.

Original languageEnglish (US)
Pages (from-to)1531-1539
Number of pages9
JournalBiochimica et Biophysica Acta - Molecular Basis of Disease
Issue number7
StatePublished - Jul 1 2015


  • Assembly
  • Mitochondrial DNA mutations
  • ND4
  • ND5
  • ND6
  • Respiratory complex I

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology


Dive into the research topics of 'Redefining the roles of mitochondrial DNA-encoded subunits in respiratory Complex I assembly'. Together they form a unique fingerprint.

Cite this