Insertion of exogenous ubiquitin into rat brain mitochondria in the presence of ATP and the ATP-regenerating system (creatine phosphate/creatine phosphokinase) is accompanied by the increase in: i) sensitivity of mitochondrial monoamine oxidases A and B to proteolytic inactivation (by trypsin and papain, respectively); ii) inhibition by mechanism based inhibitor, pargyline; iii) in [3H]-pargyline insertion into mitochondria (+48 ± 11%, p<0.01). There was almost fivefold increase in [3H]-pargyline incorporation into the fraction obtained by immunoprecipitation of mitochondrial proteins with anti-ubiquitin antiserum and protein A Sepharose. This suggests that MAO is a potential substrate for ubiquitination in vitro. However, the content of the tritium label in this fraction was less than 0.1% and not more than 0.25% of total radioactivity of [3H]pargyline bound to control and ATP-ubiquitin treated mitochondria, respectively. Insertion of ubiquitin into mitochondria did not influence molecular masses of [3H]-pargyline labeled proteins (MAO A and B). These results suggest that direct ubiquitination of MAO insignificantly contributes to marked changes in sensitivity of MAO A and MAO B to proteolysis and specific inhibition found under these experimental conditions. It is possible that more complex processes are involved into realization of these effects during ATP-dependent ubiquitin incorporation into mitochondria.
Download PDF:
Keywords: monoamine oxidase, ubiquitin, proteolytic degradation, rat brain mitochondria, pargyline
Citation:
Buneeva O.A., Medvedeva M.V., Medvedev A.E. (2008) Analysis of ubiquitin-dependent increase in monoamine oxidase sensitivity to proteolysis and specific inhibition. Biomeditsinskaya Khimiya, 54(6), 720-726.
Buneeva O.A. et al. Analysis of ubiquitin-dependent increase in monoamine oxidase sensitivity to proteolysis and specific inhibition // Biomeditsinskaya Khimiya. - 2008. - V. 54. -N 6. - P. 720-726.
Buneeva O.A. et al., "Analysis of ubiquitin-dependent increase in monoamine oxidase sensitivity to proteolysis and specific inhibition." Biomeditsinskaya Khimiya 54.6 (2008): 720-726.
Buneeva, O. A., Medvedeva, M. V., Medvedev, A. E. (2008). Analysis of ubiquitin-dependent increase in monoamine oxidase sensitivity to proteolysis and specific inhibition. Biomeditsinskaya Khimiya, 54(6), 720-726.
Grohmann U., Orabona C., Bianchi R., Belladonna M.L., Fioretti M.C., Puccetti P. (2000) Cytokine, 12, 401-404. Scholar google search
Yonashiro R., Ishido S., Kyo S., Fukuda T., Goto E., Matsuki Y., Ohmura-Hoshino M., Sada K., Hotta H., Yamamura H., Inatome R., Yanagi S. (2006) EMBO J., 25, 3618-3626. Scholar google search
