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Bernadette Schreiner
Neupert Lab
Butenandtstraße 5, Gebäude B, 81377 München
089/2180-77088 o. -77125

"Folding of Proteins in the Mitochondrial Intermembrane Space"

key words: S. cerevisiae, mitochondrial chaperone systems, unfolded protein response, proteome of the

During biogenesis of mitochondria, proteins that are encoded in the nuclear DNA are transported into one of the four different mitochondrial subcompartments. Proteins are transported across mitochondrial membranes in an unfolded state. The mature fold is obtained only after specific cleavage and folding steps. In the mitochondrial matrix, Hsp70 and Hsp60 chaperone systems help folding of newly imported proteins. In the intermembrane space (IMS), recently identified Mia40-Erv1 system couples folding with import of a subset of proteins with conserved cysteine residues. But, for other IMS proteins folding pathway still remains unexplored. The majority of these proteins are

  • since 02/2013: Postdoctoral fellow at Alzheimer's Disease Research center, Karolinska Institute, Stockholm, supervisor: Prof. Maria Ankaarcrona/ Prof. Bengt Winblad

  • 06/2008 - 01/2013: PhD student at Adolf Butenandt Institute of Physiological Chemistry,Ludwig Maximilians University Munich, supervisor: Prof. Walter Neupert

  • 06/2006 - 06/2007: Diploma thesis at Max Planck Institute of Immunobiology and Epigenetics, Freiburg/Breisgau, supervisor: prof. Rudolf Grosschedl

  • 10/2001 - 05/2006: Diploma studies of Molecular Medicine, Albert Ludwigs University Freiburg/ Breisgau

"Role of the AAA protease Yme1 in folding of proteins in the mitochondrial intermembrane space"


The vast majority of mitochondrial proteins are synthesized in the cytosol and transported into the organelle in a largely, if not completely, unfolded state. The proper function of mitochondria thus depends on folding of several hundreds of proteins in the various subcompartments of the organelle. Whereas folding of proteins in the mitochondrial matrix is supported by members of several chaperone families, very little is known about folding of proteins in the intermembrane space (IMS). We targeted dihydrofolate reductase (DHFR) as a model substrate to the IMS of yeast mitochondria and analyzed its folding. DHFR can fold in this compartment, and its aggregation upon heat shock can be prevented in an ATP-dependent manner. Yme1, an AAA (ATPases associated with diverse cellular activities) protease of the IMS, prevented aggregation of DHFR. Analysis of protein aggregates in mitochondria lacking Yme1 revealed the presence of a number of proteins involved in the establishment of mitochondrial ultrastructure, lipid metabolism, protein import, and respiratory growth. These findings explain the pleiotropic effects of deletion of YME1 and suggest an important role for Yme1 as a folding assistant, in addition to its proteolytic function, in the protein homeostasis of mitochondria.


  • 01/2009 - 01/2013: Member of the Graduate Program "Protein Dynamics in Health and Disease" of the Elite Network Bavaria
  • 11/2010 - 10/2012: Graduate Fellowship of the Bavarian Elite Promotion Act (BayEFG)

  • Organization of Company Excursions:
  1. November 2009: BASF (Ludwigshafen am Rhein)
  2. March 2010: Roche (Penzberg, Bayern)
  3. October 2010: Boehringer-Ingelheim (Biberach an der Riß)

  • Organization of Poster Presentation Workshop with Ruth Willmott

Postdoctoral Fellow at Karolinska Institute, Stockholm

Contact Info

Bernadette Schreiner
Physiologische Chemie (AK Neupert)