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The N‐terminal extension of the ADP/ATP translocator is not involved in targeting to plant mitochondria in vivo
Author(s) -
Mozo Teresa,
Fischer Karsten,
Flügge Ulf Ingo,
Schmitz Udo Klaus
Publication year - 1995
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1995.07061015.x
Subject(s) - mitochondrion , biology , translocase , biochemistry , translocator protein , microbiology and biotechnology , adenine nucleotide translocator , gene , chromosomal translocation , neuroinflammation , immunology , inflammation
The mitochondrial ADP/ATP translocator, also called adenine nucleotide translocase (ANT), is synthesized in plants with an N‐terminal extension which is cleaved upon import into mitochondria. In contrast, the homologous proteins of mammals or fungi do not contain such a transient amino terminal presequence. To investigate whether the N‐terminal extension is needed for correct intracellular sorting in vivo , translational fusions were constructed of the translocator cDNA—with and without presequence—with the β‐glucuronidase ( gus ) reporter gene. The distribution of reporter enzymatic activity in the subcellular compartments of transgenic plants and transformed yeast cells was subsequently analysed. The results show that: (i) the plant translocator presequence is not necessary for the correct localization of the ANT to the mitochondria; (ii) the mitochondrial targeting information contained in the mature part of the protein is sufficient to overcome, to some extent, the presence of plastid transit peptides; and (iii) the presequence alone is not able to target a passenger protein to mitochondria in vivo .