tRNA-triggered ATP Hydrolysis and Generation of Membrane Potential by the Leishmania Mitochondrial tRNA Import Complex
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
tRNA-triggered ATP Hydrolysis and Generation of Membrane
Potential by the Leishmania Mitochondrial tRNA Import Complex
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| Creator |
Bhattacharyya, Suvendra Nath
Adhya, Samit |
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| Subject |
Molecular & Human Genetics
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| Description |
Translocation of tRNAs across mitochondrial membranes
is a receptor-mediated active transport process
requiring ATP. A large tRNA import complex from the
inner membrane of Leishmania mitochondria catalyzes
translocation into phospholipid vesicles. In this reconstituted
system, the import substrate tRNATyr(GUA) specifically
stimulated hydrolysis of ATP within the vesicles,
with the subsequent generation of a membrane
potential by pumping out of protons, as shown by the
protonophore-sensitive uptake of the potential-sensitive
dye rhodamine 123. Generation of membrane potential
was dependent on ATP hydrolysis, and inhibited by
oligomycin, recalling the proton-translocation mechanism
of the respiratory F1-F0-ATPase. For translocation
of tRNA, ATP could be replaced by low pH of the medium,
but proton-dependent import was resistant to oligomycin.
Moreover, ATP hydrolysis, generation of membrane
potential and tRNA uptake were inhibited by
carboxyatractyloside, a specific inhibitor of mitochondrial
ATP-ADP translocase, implying an ATP requirement
within the vesicles. These observations imply a
gating mechanism in which tRNA, on binding to its receptor,
triggers the energetic activation of the complex,
leading to the opening of import channels.
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| Publisher |
American Society for Biochemistry and Molecular Biology
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| Date |
2004
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/529/1/JOURNAL_OF_BIOLOGICAL_CHEMISTRY%2C_279_(12)%2C_11259%2D11263[73].pdf
Bhattacharyya, Suvendra Nath and Adhya, Samit (2004) tRNA-triggered ATP Hydrolysis and Generation of Membrane Potential by the Leishmania Mitochondrial tRNA Import Complex. The Journal of Biological Chemistry, 279 (12). pp. 11259-11263. |
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| Relation |
http://dx.doi.org/10.1074/jbc.C300540200
http://www.eprints.iicb.res.in/529/ |
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