TAILIEUCHUNG - Báo cáo khoa học: Saccharomyces cerevisiae coq10 null mutants are responsive to antimycin A

Deletion ofCOQ10in Saccharomyces cerevisiaeelicits a respiratory defect characterized by the absence of cytochrome creduction, which is correct-able by the addition of exogenous diffusible coenzyme Q2. Unlike other coq mutants with hampered coenzyme Q6 (Q6 ) synthesis, coq10 mutants have near wild-type concentrations of Q6. | Saccharomyces cerevisiae coq10 null mutants are responsive to antimycin A Cleverson Busso1 Erich B. Tahara2 Renata Ogusucu2 Ohara Augusto2 Jose Ribamar Ferreira-Junior3 Alexander Tzagoloff4 Alicia J. Kowaltowski2 and Mario H. Barros1 1 Departamento de Microbiologia Institute de Ciencias Biomedicas Universidade de Sao Paulo Brazil 2 Departmento de Bioquimica Instituto de Quimica Universidade de Sao Paulo Brazil 3 Escola de Artes Ciencias e Humanidades Universidade de Sao Paulo Brazil 4 Department of BiologicalSciences Columbia University New York NY USA Keywords coenzyme Q mitochondria Saccharomyces cerevisiae Correspondence M. H. Barros Departamento de Microbiologia Instituto de Ciencias Biomedicas Universidade de Sao Paulo Av. Professor Lineu Prestes 1374 05508-900 Sao Paulo Brazil Fax 55 11 30917354 Tel 55 11 30918456 E-mail mariohb@ Received 16 June 2010 revised 3 August 2010 accepted 3 September 2010 doi Deletion of COQ10 in Saccharomyces cerevisiae elicits a respiratory defect characterized by the absence of cytochrome c reduction which is correctable by the addition of exogenous diffusible coenzyme Q2. Unlike other coq mutants with hampered coenzyme Q6 Q6 synthesis coq10 mutants have near wild-type concentrations of Q6. In the present study we used Q-cycle inhibitors of the coenzyme QH2-cytochrome c reductase complex to assess the electron transfer properties of coq10 cells. Our results show that coq10 mutants respond to antimycin A indicating an active Q-cycle in these mutants even though they are unable to transport electrons through cytochrome c and are not responsive to myxothiazol. EPR spectroscopic analysis also suggests that wild-type and coq10 mitochondria accumulate similar amounts of Q6 semiquinone despite a lower steady-state level of coenzyme QH2-cytochrome c reductase complex in the coq10 cells. Confirming the reduced respiratory chain state in coq10 cells we found that the expression of the Aspergillus .

TỪ KHÓA LIÊN QUAN
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.