![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
|
|
|
|
|
||
A more recent version of this article appeared on February 1, 2003
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on May 7, 2002
Revised on August 26, 2002
Accepted on October 16, 2002
1 Institut für Biochemie, Technische Universität Graz, Petersgasse 12/2, A-8010 Graz, Austria
2 Institut für Biochemie, Technische Universität Graz, Petersgasse 12/2, A-8010 Graz, Austria (present address: Department of Medicine, Division of Biochemistry, University of Fribourg, Switzerland)
* Corresponding author. E-mail address: guenther.daum{at}tugraz.at.
The majority of mitochondrial phosphatidylethanolamine (PtdEtn), a phospholipid essential for aerobic growth of yeast cells, is synthesized by phosphatidylserine decarboxylase 1 (Psd1p) in the inner mitochondrial membrane (IMM). To identify components which become essential when the level of mitochondrial PtdEtn is decreased, we screened for mutants that are synthetically lethal with a temperature-sensitive (ts) allele of PSD1. This screen unveiled mutations in PHB1 and PHB2 encoding the two subunits of the prohibitin complex, which is located to the IMM and required for the stability of mitochondrially encoded proteins. Deletion of PHB1 and PHB2 resulted in an increase of mitochondrial PtdEtn at 30°C. On glucose media, phb1
psd1 and phb2 psd1 double mutants were rescued only for a limited number of generations by exogenous Etn, indicating that a decrease of the PtdEtn level is detrimental for prohibitin mutants. Similar to phb mutants, deletion of PSD1 destabilizes polypeptides encoded by the mitochondrial genome. In a phb1 phb2 psd1ts strain the destabilizing effect is dramatically enhanced. In addition, the mitochondrial genome is lost in this triple mutant, and nuclear encoded proteins of the IMM are assembled at a very low rate. At the non-permissive temperature mitochondria of phb1 phb2 psd1ts were fragmented and aggregated. In conclusion, destabilizing effects triggered by low levels of mitochondrial PtdEtn appear to account for synthetic lethality of psd1 with phb mutants.
This article has been cited by other articles:
|
|
 |
|
  R. Nebauer, S. Rosenberger, and G. Daum Phosphatidylethanolamine, a Limiting Factor of Autophagy in Yeast Strains Bearing a Defect in the Carboxypeptidase Y Pathway of Vacuolar Targeting J. Biol. Chem., June 8, 2007; 282(23): 16736 - 16743. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Osman, C. Wilmes, T. Tatsuta, and T. Langer Prohibitins Interact Genetically with Atp23, a Novel Processing Peptidase and Chaperone for the F1FO-ATP Synthase Mol. Biol. Cell, February 1, 2007; 18(2): 627 - 635. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Tatsuta, K. Model, and T. Langer Formation of Membrane-bound Ring Complexes by Prohibitins in Mitochondria Mol. Biol. Cell, January 1, 2005; 16(1): 248 - 259. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Sanz, W. Y. Tsang, E. M. Willems, L. A. Grivell, B. D. Lemire, H. van der Spek, and L. G. J. Nijtmans The Mitochondrial Prohibitin Complex Is Essential for Embryonic Viability and Germline Function in Caenorhabditis elegans J. Biol. Chem., August 22, 2003; 278(34): 32091 - 32099. [Abstract] [Full Text] [PDF]
|
|
