Genetic and pharmacological inhibition of autophagy increases the monoubiquitination of non-photosynthetic phosphopyruvate carboxylase

Baena, G. , Feria, A. B., Hernández-Huertas, L., Gandullo, J., Echevarría, C., Monreal, J. A. and García-Mauriño, S. (2021) Genetic and pharmacological inhibition of autophagy increases the monoubiquitination of non-photosynthetic phosphopyruvate carboxylase. Plants, 10(1), 12. (doi: 10.3390/plants10010012) (PMID:33374865) (PMCID:PMC7823769)

Abstract

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.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Baena, Dr Guillermo

Creator Roles

Baena, G.: Conceptualization, Methodology, Investigation, Writing – original draft

• Authors: Baena, G., Feria, A. B., Hernández-Huertas, L., Gandullo, J., Echevarría, C., Monreal, J. A., and García-Mauriño, S.
• Subjects: Q Science > Q Science (General)
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Plants
• Publisher: MDPI
• ISSN: 2223-7747
• ISSN (Online): 2223-7747
• Published Online: 23 December 2020
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Plants 10(1): 12
• Publisher Policy: Reproduced under a Creative Commons License