Identification of Tom5 and Tom6 in the preprotein translocase complex of human mitochondrial outer membrane

Hiroki Kato, Katsuyoshi Mihara

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

The fungal preprotein translocase of the mitochondrial outer membrane (TOM complex) comprises import receptors Tom70, Tom20, and Tom22, import channel Tom40, and small Tom proteins Tom5, Tom6, and Tom7, which regulate TOM complex assembly. These components are conserved in mammals; unlike the other components, however, Tom5 and Tom6 remain unidentified in mammals. We immuno-isolated the TOM complex from HeLa cells expressing hTom22-FLAG and identified the human counterparts of Tom5 and Tom6, together with the other components including Tom7. These small Tom proteins are associated with Tom40 in the TOM complex. Knockdown of Tom7, but not Tom5 and Tom6, strongly compromised stability of the TOM complex. Conversely, knockdown of hTom40 decreased the level of all small Tom proteins. Matrix import of preprotein was affected by double knockdown of any combination of small Tom proteins. These results indicate that human small Tom proteins maintain the structural integrity of the TOM complex.

Original languageEnglish
Pages (from-to)958-963
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume369
Issue number3
DOIs
Publication statusPublished - May 9 2008

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Mitochondrial Membranes
Membranes
Mammals
Proteins
Structural integrity
HeLa Cells
TOM translocase
Cells

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

Identification of Tom5 and Tom6 in the preprotein translocase complex of human mitochondrial outer membrane. / Kato, Hiroki; Mihara, Katsuyoshi.

In: Biochemical and Biophysical Research Communications, Vol. 369, No. 3, 09.05.2008, p. 958-963.

Research output: Contribution to journalArticle

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