Stepwise transfer of tRNA through the double membrane of Leishmania mitochondria

Mukherjee, Shankar ; Bhattacharyya, Subhendra Nath ; Adhya, Samit (1999) Stepwise transfer of tRNA through the double membrane of Leishmania mitochondria Journal of Biological Chemistry, 274 (44). pp. 31249-31255. ISSN 0021-9258

PDF - Publisher Version

Official URL:

Related URL:


Import of tRNA into Leishmaniamitochondria involves transfer through a double membrane barrier. To examine whether specific sorting mechanisms for individual tRNAs direct them to different mitochondrial compartments, the distribution of tRNA transcripts, internalized in vitro, was examined by suborganellar fractionation. Significant amounts of tRNATyrwere localized in the matrix and on the outer face of the inner mitochondrial membrane. With time, the matrix:membrane ratio increased. Translocation through the inner membrane apparently required the presence of a specific signal in the D arm of tRNATyr, and tRNAGln(CUG), lacking this sequence, was excluded. Hydrolysis of ATP was necessary at both the outer and inner membranes. However, the protonophores carbonylcyanide m-chlorophenylhydrazone and nigericin, the K+ionophore valinomycin, and the F1F0 ATPase inhibitor oligomycin had only marginal effects on uptake through the outer membrane but severely inhibited inner membrane translocation, indicating the unusual requirement of both the electrical and chemical components of the electromotive force generated across the inner membrane. The results are consistent with a mechanism involving stepwise transfer of tRNA through distinct outer and inner membrane channels.

Item Type:Article
Source:Copyright of this article belongs to American Society for Biochemistry and Molecular Biology.
ID Code:12059
Deposited On:09 Nov 2010 11:45
Last Modified:16 May 2016 21:27

Repository Staff Only: item control page