title: Tyrosine phosphorylation by Src within the cavity of the adenine nucleotide translocase 1 regulates ADP/ATP exchange in mitochondria.
abstract: Phosphorylation of adenine nucleotide translocator 1 (ANT1) at residue Y194, which is part of the aromatic ladder located within the lumen of the carrier, critically regulates mitochondrial metabolism. Recent data support the concept that members of the Src family of nonreceptor tyrosine kinases are constitutively present in mitochondria and key to regulation of mitochondrial function. Herein, we demonstrate that site mutations of ANT1 (Y190-->F190, Y194-->F194) mimicking dephosphorylation of the aromatic ladder resulted in loss of oxidative growth and ADP/ATP exchange activity in respiration-incompetent yeast expressing mutant chimeric yN-hANT1. ANT1 is phosphorylated at Y194 by the Src family kinase members Src and Lck, and increased phosphorylation is tightly linked to reduced cell injury in preconditioned protected vs. unprotected cardiac mitochondria. Molecular dynamics simulations find the overall structure of the phosphorylated ANT1 stable, but with an increased steric flexibility in the region of the aromatic ladder, matrix loop m2, and four helix-linking regions. Combined with an analysis of the putative cytosolic salt bridge network, we reason that the effect of phosphorylation on transport is likely due to an accelerated transition between the main two conformational states (c<-->m) of the carrier during the transport cycle. Since "aromatic signatures" are typical for other mitochondrial carrier proteins with important biological functions, our results may be more general and applicable to these carriers.
authors.affiliation: Dept. of Anesthesiology and Pain Medicine, Univ. of Alberta, Clinical Sciences Bldg. Rm. 8-120, 113 St. 83 Ave., Edmonton, AB T6G 2G3, Canada.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Feng
authors.forename: Eliana
authors.initials: E
authors.lastname: Lucchinetti
authors.forename: Giray
authors.initials: G
authors.lastname: Enkavi
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Peter
authors.initials: P
authors.lastname: Gehrig
authors.forename: Bernd
authors.initials: B
authors.lastname: Roschitzki
authors.forename: Marcus C
authors.initials: MC
authors.lastname: Schaub
authors.forename: Emad
authors.initials: E
authors.lastname: Tajkhorshid
authors.forename: Kathrin
authors.initials: K
authors.lastname: Zaugg
authors.forename: Michael
authors.initials: M
authors.lastname: Zaugg
mesh_terms: D033741:Adenine Nucleotide Translocator 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D003198:Computer Simulation; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology*; D000226:Mitochondrial ADP, ATP Translocases / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009206:Myocardium / Q000201:enzymology; D033704:Nucleotide Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011487:Protein Conformation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D011743:Pyrimidines / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014162:Transfection; D014443:Tyrosine; D014638:Vanadates / Q000494:pharmacology; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: C412373:AG 1879; C430871:ANT1 protein, S cerevisiae; D033741:Adenine Nucleotide Translocator 1; D033704:Nucleotide Transport Proteins; C112225:PET9 protein, S cerevisiae; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C076715:pervanadate; D014638:Vanadates; D014443:Tyrosine; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000226:Mitochondrial ADP, ATP Translocases; D006861:Hydrogen Peroxide; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D019061:src-Family Kinases