tailieunhanh - Báo cáo khoa học: A distinct sequence in the adenine nucleotide translocase from Artemia franciscana embryos is associated with insensitivity to bongkrekate and atypical effects of adenine nucleotides on Ca2+ uptake and sequestration

Mitochondria isolated from embryos of the crustaceanArtemia franciscana lack the Ca 2+ -induced permeability transition pore. Although the composi-tion of the pore described in mammalian mitochondria is unknown, the impacts of several effectors of the adenine nucleotide translocase (ANT) on pore opening are firmly established. | BFEBS Journal A distinct sequence in the adenine nucleotide translocase from Artemia franciscana embryos is associated with insensitivity to bongkrekate and atypical effects of adenine nucleotides on Ca2 uptake and sequestration Csaba Konrad1 Gergely Kiss1 Beata Torocsik1 Janos L. Labar2 Akos A. Gerencser3 Miklos Mandi1 Vera Adam-Vizi1 and Christos Chinopoulos1 1 Department of MedicalBiochemistry Semmelweis University Budapest Hungary 2 Research Institute for TechnicalPhysics and Materials Science Budapest Hungary 3 Buck Institute for Age Research Novato CA USA Keywords adenine nucleotide carrier adenine nucleotide translocator bongkrekic acid diapause Correspondence C. Chinopoulos Department of Medical Biochemistry Semmelweis University Budapest Hungary Fax 361 2670031 Tel 361 4591500 ext. 60024 E-mail Received 22 October 2010 revised 30 November 2010 accepted 23 December 2010 doi Mitochondria isolated from embryos of the crustacean Artemia franciscana lack the Ca2 -induced permeability transition pore. Although the composition of the pore described in mammalian mitochondria is unknown the impacts of several effectors of the adenine nucleotide translocase ANT on pore opening are firmly established. Notably ADP ATP and bongkrekate delay whereas carboxyatractyloside hastens Ca2 -induced pore opening. Here we report that adenine nucleotides decreased whereas carboxyatract-yloside increased Ca2 uptake capacity in mitochondria isolated from Artemia embryos. Bongkrekate had no effect on either Ca2 uptake or ADP-ATP exchange rate. Transmission electron microscopy imaging of Ca2 -loaded Artemia mitochondria showed needle-like formations of electron-dense material in the absence of adenine nucleotides and dot-like formations in the presence of adenine nucleotides or Mg2 . Energy-filtered transmission electron microscopy showed the material to be rich in calcium and phosphorus. Sequencing of the Artemia mRNA