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The enteropathogenic Escherichia coli (EPEC) Map effector is imported into the mitochondrial matrix by the TOM/Hsp70 system and alters organelle morphology
- Source :
- Cellular microbiology. 8(4)
- Publication Year :
- 2006
-
Abstract
- Enteropathogenic Escherichia coli (EPEC) is a human intestinal pathogen and a major cause of diarrhoea, particularly among infants in developing countries. EPEC target the Map and EspF multifunctional effector proteins to host mitochondria - organelles that play crucial roles in regulating cellular processes such as programmed cell death (apoptosis). While both molecules interfere with the organelles ability to maintain a membrane potential, EspF plays the predominant role and is responsible for triggering cell death. To learn more about the Map-mitochondria interaction, we studied Map localization to mitochondria with purified mitochondria (from mammalian and yeast cells) and within intact yeast. This revealed that (i) Map targeting is dependent on the predicted N-terminal mitochondrial targeting sequence, (ii) the N-terminal 44 residues are sufficient to target proteins to mitochondria and (iii) Map import involves the mitochondrial outer membrane translocase (Tom22 and Tom40), the mitochondrial membrane potential, and the matrix chaperone, mtHsp70. These results are consistent with Map import into the mitochondria matrix via the classical import mechanism. As all known, Map-associated phenotypes in mammalian cells are independent of mitochondrial targeting, this may indicate that import serves as a mechanism to remove Map from the cytoplasm thereby regulating cytoplasmic function. Intriguingly, Map, but not EspF, alters mitochondrial morphology with deletion analysis revealing important roles for residues 101-152. Changes in mitochondrial morphology have been linked to alterations in the ability of these organelles to regulate cellular processes providing a possible additional role for Map import into mitochondria.
- Subjects :
- Saccharomyces cerevisiae Proteins
Immunology
Amino Acid Motifs
Molecular Sequence Data
Apoptosis
Saccharomyces cerevisiae
Mitochondrion
In Vitro Techniques
Microbiology
Mitochondrial Membrane Transport Proteins
Membrane Potentials
Mitochondrial membrane transport protein
Virology
Escherichia coli
Translocase
Animals
HSP70 Heat-Shock Proteins
Amino Acid Sequence
biology
Effector
Escherichia coli Proteins
Intracellular Signaling Peptides and Proteins
Membrane Transport Proteins
Transport protein
Cell biology
Mitochondria
Rats
Protein Transport
Biochemistry
Cytoplasm
Chaperone (protein)
Mitochondrial Membranes
biology.protein
Rabbits
Bacterial outer membrane
Carrier Proteins
Subjects
Details
- ISSN :
- 14625814
- Volume :
- 8
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Cellular microbiology
- Accession number :
- edsair.doi.dedup.....ed7d988900b153f72aed020dde8bb5db