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TMEM65 is a mitochondrial inner-membrane protein.
Naotaka Nishimura1, Tomomi Gotoh2, Yuichi Oike1
1Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University , Kumamoto , Japan.
Peerj
|April 26, 2014
Summary
The protein TMEM65 localizes to the inner mitochondrial membrane. This protein is imported into mitochondria and processed by the matrix processing protease (MPP).
Area of Science:
- Mitochondrial biology
- Molecular cell biology
Background:
- The regulation of TMEM65 expression by steroid receptor RNA activator (SRA) has been reported.
- The intracellular localization and function of TMEM65 remain largely unknown.
Purpose of the Study:
- To determine the intracellular localization and membrane topology of TMEM65.
- To elucidate the mechanism of TMEM65 import and processing within mitochondria.
Main Methods:
- Immunoblot and immunostaining analyses were employed to detect TMEM65.
- Alkali and digitonin extraction methods were used on isolated mitochondria to assess membrane association.
- Deletion mutants of TMEM65 were analyzed to identify mitochondrial targeting signals.
Main Results:
- TMEM65 was found to localize to mitochondria.
- Further analysis revealed TMEM65 as an integral inner mitochondrial membrane protein.
- The N-terminal region (1-20) contains a mitochondrial targeting signal (MTS) that is processed between amino acids 35 and 64 by matrix processing protease (MPP).
Conclusions:
- TMEM65 is imported into mitochondria.
- TMEM65 integrates into the mitochondrial inner membrane.
- The protein undergoes proteolytic processing by MPP to reach its mature form.
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