Translocation of mitochondrial inner-membrane proteins: conformation matters

2006 ◽  
Vol 31 (5) ◽  
pp. 259-267 ◽  
Author(s):  
Carine de Marcos-Lousa ◽  
Dionisia P Sideris ◽  
Kostas Tokatlidis
Keyword(s):  
Membrane Proteins ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane

scholarly journals Fmp30, Mdm31, and Mdm32 Function in Ups1-Independent Cardiolipin Accumulation Under Low Phosphatidylethanolamine Conditions

Contact ◽  
2018 ◽  
Vol 1 ◽  
pp. 251525641876404
Author(s):  
Non Miyata ◽  
Osamu Kuge
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Membrane Proteins ◽  
Phosphatidic Acid ◽  
Yeast Saccharomyces Cerevisiae ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Per Se

Maintenance of the cardiolipin (CL) level largely depends on Ups1-Mdm35 complex-mediated intramitochondrial phosphatidic acid transfer. In addition, the presence of an alternative CL accumulation pathway has been suggested in the yeast Saccharomyces cerevisiae. This pathway is independent of the Ups1-Mdm35 complex and stimulated by loss of Ups2, which forms a complex with Mdm35 and mediates intramitochondrial transfer of phosphatidylserine for phosphatidylethanolamine synthesis. Recently, we found that the alternative CL accumulation pathway is enhanced by a lowered phosphatidylethanolamine level, not by loss of Ups2 per se, and depends on three mitochondrial inner membrane proteins, Fmp30, Mdm31, and Mdm32.

scholarly journals Role of positively charged transmembrane segments in the insertion and assembly of mitochondrial inner-membrane proteins

2001 ◽  
Vol 98 (24) ◽  
pp. 13814-13819 ◽  
Author(s):  
Y. Saint-Georges ◽  
P. Hamel ◽  
C. Lemaire ◽  
G. Dujardin
Keyword(s):  
Membrane Proteins ◽  
Inner Membrane ◽  
Transmembrane Segments ◽  
Mitochondrial Inner Membrane ◽  
Positively Charged

AAA proteases of mitochondria: quality control of membrane proteins and regulatory functions during mitochondrial biogenesis

2001 ◽  
Vol 29 (4) ◽  
pp. 431-436 ◽  
Author(s):  
T. Langer ◽  
M. Käser ◽  
C. Klanner ◽  
K. Leonhard
Keyword(s):  
Quality Control ◽  
Membrane Proteins ◽  
Matrix Space ◽  
Inner Membrane ◽  
Membrane Surfaces ◽  
Mitochondrial Inner Membrane ◽  
Catalytic Sites ◽  
The Matrix ◽  
The Stability ◽  
Regulatory Functions

An ubiquitous and conserved proteolytic system regulates the stability of mitochondrial inner membrane proteins. Two AAA proteases with catalytic sites at opposite membrane surfaces form a membrane-integrated quality control system and exert crucial functions during the biogenesis of mitochondria. Their activity is modulated by another membrane-protein complex that is composed of prohibitins. Peptides generated upon proteolysis in the matrix space are transported across the inner membrane by an ATP-binding cassette transporter. The function of these conserved components is discussed in the present review.

scholarly journals Divergent Small Tim Homologues Are Associated with TbTim17 and Critical for the Biogenesis of TbTim17 Protein Complexes in Trypanosoma brucei

mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Joseph T. Smith ◽  
Ujjal K. Singha ◽  
Smita Misra ◽  
Minu Chaudhuri
Keyword(s):  
Membrane Proteins ◽  
Trypanosoma Brucei ◽  
Mitochondrial Protein ◽  
Intermembrane Space ◽  
Inner Membrane ◽  
Content Type ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Intermembrane Space ◽  
The Stability ◽  
Tim Proteins

ABSTRACT The small Tim proteins belong to a group of mitochondrial intermembrane space chaperones that aid in the import of mitochondrial inner membrane proteins with internal targeting signals. Trypanosoma brucei , the protozoan parasite that causes African trypanosomiasis, possesses multiple small Tim proteins that include homologues of T. brucei Tim9 (TbTim9) and Tim10 (TbTim10) and a unique small Tim that shares homology with both Tim8 and Tim13 (TbTim8/13). Here, we found that these three small TbTims are expressed as soluble mitochondrial intermembrane space proteins. Coimmunoprecipitation and mass spectrometry analysis showed that the small TbTims stably associated with each other and with TbTim17, the major component of the mitochondrial inner membrane translocase in T. brucei . Yeast two-hybrid analysis indicated direct interactions among the small TbTims; however, their interaction patterns appeared to be different from those of their counterparts in yeast and humans. Knockdown of the small TbTims reduced cell growth and decreased the steady-state level of TbTim17 and T. brucei ADP/ATP carrier (TbAAC), two polytopic mitochondrial inner membrane proteins. Knockdown of small TbTims also reduced the matured complexes of TbTim17 in mitochondria. Depletion of any of the small TbTims reduced TbTim17 import moderately but greatly hampered the stability of the TbTim17 complexes in T. brucei . Altogether, our results revealed that TbTim9, TbTim10, and TbTim8/13 interact with each other, associate with TbTim17, and play a crucial role in the integrity and maintenance of the levels of TbTim17 complexes. IMPORTANCE Trypanosoma brucei is the causative agent of African sleeping sickness. The parasite’s mitochondrion represents a useful source for potential chemotherapeutic targets. Similarly to yeast and humans, mitochondrial functions depend on the import of proteins that are encoded in the nucleus and made in the cytosol. Even though the machinery involved in this mitochondrial protein import process is becoming clearer in T. brucei , a comprehensive picture of protein complex composition and function is still lacking. In this study, we characterized three T. brucei small Tim proteins, TbTim9, TbTim10, and TbTim8/13. Although the parasite does not have the classical TIM22 complex that imports mitochondrial inner membrane proteins containing internal targeting signals in yeast or humans, we found that these small TbTims associate with TbTim17, the major subunit of the TbTIM complex in T. brucei , and play an essential role in the stability of the TbTim17 complexes. Therefore, these divergent proteins are critical for mitochondrial protein biogenesis in T. brucei .

scholarly journals Affinity chromatography purification of mitochondrial inner membrane proteins with calcium transport activity

1998 ◽  
Vol 1373 (2) ◽  
pp. 347-359 ◽  
Author(s):  
Ana Villa ◽  
Maria Isabel García-Simón ◽  
Pablo Blanco ◽  
Bárbara Sesé ◽  
Elena Bogónez ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Affinity Chromatography ◽  
Calcium Transport ◽  
Transport Activity ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane

Age-related decline in the biosynthesis of mitochondrial inner membrane proteins

1982 ◽  
Vol 17 (5) ◽  
pp. 333-341 ◽  
Author(s):  
David L. Marcus ◽  
Nader G. Ibrahim ◽  
Michael L. Freedman
Keyword(s):  
Membrane Proteins ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Age Related

Isolation of tryptic fragment of antigen from mitochondrial inner membrane proteins reacting with antimitochondrial antibody in sera of patients with primary biliary cirrhosis

Hepatology ◽  
1990 ◽  
Vol 11 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Daisaku Muno ◽  
Eiki Kominami ◽  
Hideo Ishii ◽  
Koh Usui ◽  
Koji Saifuku ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Primary Biliary Cirrhosis ◽  
Biliary Cirrhosis ◽  
Inner Membrane ◽  
Tryptic Fragment ◽  
Antimitochondrial Antibody ◽  
Mitochondrial Inner Membrane
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