Christopher Carrie - Plant mitochondrial inner membrane protein translocation pathways

  • Datum: 19.04.2017
  • Uhrzeit: 14:00 - 15:30
  • Vortragende(r): Christopher Carrie
  • Ort: Central Building
  • Raum: Seminar Room
  • Gastgeber: Etienne Meyer
Plant mitochondria differ significantly from those found in other organisms which has led to the evolution of distinct strategies for genome maintenance, genetic coding, gene regulation, organelle segregation and also protein import pathways. The mitochondrial import apparatus is composed of a number of evolutionary related multi-subunit protein complexes that recognize, translocate and assemble mitochondrial proteins. Our recent work has shown that the translocation pathways found in plant mitochondria are notably different compared to those of other model organisms. We have recently discovered that plant mitochondria contain an essential Twin arginine translocation pathway within the inner membrane. This mitochondrial Tat pathway is at least responsible for the translocation of the Rieske Fe/S protein from complex III but may also have other substrates. Plant mitochondria also contain four members of the YidC/Oxa1/Alb3 family of proteins in contrast to other organisms which normally only contain two. It has been demonstrated that three of these plant Oxa proteins namely Oxa1A, Oxa2A and Oxa2B are essential. The Oxa2A and Oxa2B proteins are unique to the plant kingdom in that they harbor TPR repeats at their C-termini. Our recent work has demonstrated that while the proteins are essential the TPR domain is not. Plants complemented with Oxa2 proteins lacking the TPR domain are viable but severely developmentally delayed. Our recent results in studying the roles and functions of Oxa proteins and the mitochondrial Tat pathway in plant mitochondrial biogenesis will be discussed.
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