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Mitochondrial protein import: Differential recognition of various transport intermediates by antibodies
Author(s) -
Söllner Thomas,
Pfanner Nikolaus,
Neupert Walter
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)80790-7
Subject(s) - mitochondrion , protein subunit , chromosomal translocation , bacterial outer membrane , inner mitochondrial membrane , translocase of the inner membrane , membrane , microbiology and biotechnology , atpase , mitochondrial membrane transport protein , chemistry , mitochondrial carrier , biochemistry , transport protein , antibody , biology , biophysics , enzyme , escherichia coli , immunology , gene
The precursors of the mitochondrial proteins ADP/ATP carrier (AAC) and F 1 ‐ATPase subunit β (F 1 β) were accumulated at the stages of binding to receptor sites on the mitochondrial outer membrane, or in contact sites between outer and inner membranes. Specific antibodies raised against the mature proteins were added to the isolated mitochondria and efficiently bound to these translocation intermediates. Further movement of the precursors to consecutive steps along their import pathway was thereby inhibited. Controls showed that precursor proteins which were inserted into or translocated across the outer membrane were not recognized by the antibodies unless the mitochondrial membranes were disrupted. We conclude that the trapped translocation intermediates have antigenic sites exposed to the outside of the outer membrane.