“Ping-Pong” Interactions between Mitochondrial tRNA Import Receptors within a Multiprotein Complex
Subhendra Nath Bhattacharyya,Saibal Chatterjee,Srikanta Goswami,Gayatri Tripathi,Sailendra Nath Dey,Samit Adhya +5 more
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TLDR
By a combination of antibody inhibition, photochemical cross-linking, and immunoprecipitation, it was shown that binding of tRNAIle to a 21-kDa component of the complex is dependent upon tRNATyr, whilebinding of tR NATyr to a 45-KDa component is inhibited by t RNAIle, suggesting this “ping-pong” mechanism may be an effective means to maintain a balanced tRNA pool for mitochondrial translation.Abstract:
The mitochondrial genomes of a wide variety of species contain an insufficient number of functional tRNA genes, and translation of mitochondrial mRNAs is sustained by import of nucleus-encoded tRNAs. In Leishmania, transfer of tRNAs across the inner membrane can be regulated by positive and negative interactions between them. To define the factors involved in such interactions, a large multisubunit complex (molecular mass, approximately 640 kDa) from the inner mitochondrial membrane of the kinetoplastid protozoon Leishmania, consisting of approximately 130-A particles, was isolated. The complex, when incorporated into phospholipid vesicles, induced specific, ATP- and proton motive force-dependent transfer of Leishmania tRNA(Tyr) as well as of oligoribonucleotides containing the import signal YGGYAGAGC. Moreover, allosteric interactions between tRNA(Tyr) and tRNA(Ile) were observed in the RNA import complex-reconstituted system, indicating the presence of primary and secondary tRNA binding sites within the complex. By a combination of antibody inhibition, photochemical cross-linking, and immunoprecipitation, it was shown that binding of tRNA(Ile) to a 21-kDa component of the complex is dependent upon tRNA(Tyr), while binding of tRNA(Tyr) to a 45-kDa component is inhibited by tRNA(Ile). This "ping-pong" mechanism may be an effective means to maintain a balanced tRNA pool for mitochondrial translation.read more
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Necessary and sufficient factors for the import of transfer RNA into the kinetoplast mitochondrion
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Import of nuclear DNA-encoded RNAs into mitochondria and mitochondrial translation.
Ivan Tarassov,Piotr Kamenski,Olga Kolesnikova,Olga Karicheva,Robert P. Martin,Igor A. Krasheninnikov,Nina Entelis +6 more
TL;DR: An original mechanism of conditional regulation of mitochondrial translation exploiting the RNA import pathway is discovered in yeast and the possible impact of the newly described mechanism of translational adaptation is discussed.
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Selection of RNA aptamers imported into yeast and human mitochondria
Olga Kolesnikova,Helena Kazakova,Caroline Comte,Sergey V. Steinberg,Piotr Kamenski,Robert P. Martin,Ivan Tarassov,Nina Entelis +7 more
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