“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
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
Citations
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A bifunctional tRNA import receptor from Leishmania mitochondria
Srikanta Goswami,Gunjan Dhar,Saikat Mukherjee,Bidesh Mahata,Saibal Chatterjee,Pratik Home,Samit Adhya +6 more
TL;DR: In kinetoplastid protozoa, import of cytosolic tRNAs into mitochondria occurs through t RNAs interacting with membrane-bound proteins, the identities of which are unknown, and RIC1/F1alpha is a type I tRNA import receptor.
Journal ArticleDOI
Correction of Translational Defects in Patient-derived Mutant Mitochondria by Complex-mediated Import of a Cytoplasmic tRNA
TL;DR: It is shown that a protein complex from the kinetoplastid protozoon Leishmania induces specific, ATP-dependent import of human cytoplasmic tRNA into human mitochondria in vitro, suggesting a novel way to introduce RNAs for the modulation of mitochondrial gene expression.
Journal ArticleDOI
Targeting nucleic acids into mitochondria: progress and prospects.
Adnan Khan Niazi,Daria Mileshina,Anne Cosset,Romain Val,Frédérique Weber-Lotfi,André Dietrich +5 more
TL;DR: A number of alternative approaches based on RNA trafficking were also established and will bring as well major contributions to the field and are the subject of the present review.
Journal ArticleDOI
The Complexity of Mitochondrial tRNA Import
TL;DR: The purpose of this review is to summarize recent developments that shed new light on the selectivity of the process, the identity of the import apparatus and the nature of the bioenergetic transactions leading to tRNA translocation, and to build a working model of theImport complex suggested by these observations.
Journal ArticleDOI
Leishmania mitochondrial tRNA importers.
TL;DR: RIC was shown to act as an efficient delivery vehicle for tRNA and other small RNAs into mitochondria within intact mammalian cells, indicating its applicability to the management of diseases caused by mitochondrial mutations.
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