Genetic and Pharmacological Inhibition of Autophagy Increases the Monoubiquitination of Non-Photosynthetic Phosphoenolpyruvate Carboxylase
|Baena Vaca, Guillermo
Feria Bourrellier, Ana Belén
Hernández Huertas, Luis
Gandullo Tovar, Jacinto Manuel
Echevarría Ruiz de Vargas, Cristina
Monreal Hermoso, José Antonio
García-Mauriño Ruiz-Berdejo, Sofía
|Universidad de Sevilla. Departamento de Biología Vegetal y Ecología
|Phosphoenolpyruvate carboxylase (PEPC) is an enzyme with key roles in carbon and nitrogen metabolisms. The mechanisms that control enzyme stability and turnover are not well known. This paper investigates the degradation ...
Phosphoenolpyruvate carboxylase (PEPC) is an enzyme with key roles in carbon and nitrogen metabolisms. The mechanisms that control enzyme stability and turnover are not well known. This paper investigates the degradation of PEPC via selective autophagy, including the role of the monoubiquitination of the enzyme in this process. In Arabidopsis, the genetic inhibition of autophagy increases the amount of monoubiquitinated PEPC in the atg2, atg5, and atg18a lines. The same is observed in nbr1, which is deficient in a protein that recruits monoubiquitinated substrates for selective autophagy. In cultured tobacco cells, the chemical inhibition of the degradation of autophagic substrates increases the quantity of PEPC proteins. When the formation of the autophagosome is blocked with 3-methyladenine (3-MA), monoubiquitinated PEPC accumulates as a result. Finally, pull-down experiments with a truncated version of NBR1 demonstrate the recovery of intact and/or fragmented PEPC in Arabidopsis leaves and roots, as well as cultured tobacco cells. Taken together, the results show that a fraction of PEPC is cleaved via selective autophagy and that the monoubiquitination of the enzyme has a role in its recruitment towards this pathway. Although autophagy seems to be a minor pathway, the results presented here increase the knowledge about the role of monoubiquitination and the regulation of PEPC degradation.
|Junta de Andalucía
Ministerio de Economía y Competitividad (MINECO). España
|P12-FQM-489 and PAI group BIO298
AGL2012-35708 and AGL2016-75413-P
|Baena Vaca, G., Feria Bourrellier, A.B., Hernández Huertas, L., Gandullo Tovar, J.M., Echevarría Ruiz de Vargas, C., Monreal Hermoso, J.A. y García-Mauriño Ruiz-Berdejo, S. (2021). Genetic and Pharmacological Inhibition of Autophagy Increases the Monoubiquitination of Non-Photosynthetic Phosphoenolpyruvate Carboxylase. Plants, 10 (1), 12.