Dataset Information

Anionic Phospholipids Induce Conformational Changes in Phosphoenolpyruvate Carboxylase to Increase Sensitivity to Cathepsin Proteases.

ABSTRACT: Phosphoenolpyruvate carboxylase (PEPC) is a cytosolic, homotetrameric enzyme that serves a variety of functions in plants, acting as the primary form of CO₂ fixation in the C₄ photosynthesis pathway (C₄-PEPC). In a previous work we have shown that C₄-PEPC bind anionic phospholipids, resulting in PEPC inactivation. Also, we showed that PEPC can associate with membranes and to be partially proteolyzed. However, the mechanism controlling this remains unknown. Using semi purified-PEPC from sorghum leaf and a panel of PEPC-specific antibodies, we analyzed the conformational changes in PEPC induced by anionic phospholipids to cause the inactivation of the enzyme. Conformational changes observed involved the exposure of the C-terminus of PEPC from the native, active enzyme conformation. Investigation of the protease activity associated with PEPC demonstrated that cysteine proteases co-purify with the enzyme, with protease-specific substrates revealing cathepsin B and L as the major protease species present. The anionic phospholipid-induced C-terminal exposed conformation of PEPC appeared highly sensitive to the identified cathepsin protease activity and showed initial proteolysis of the enzyme beginning at the N-terminus. Taken together, these data provide the first evidence that anionic phospholipids promote not only the inactivation of the PEPC enzyme, but also its proteolysis.

SUBMITTER: Gandullo J

PROVIDER: S-EPMC6521631 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

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Anionic Phospholipids Induce Conformational Changes in Phosphoenolpyruvate Carboxylase to Increase Sensitivity to Cathepsin Proteases.

Gandullo Jacinto J Monreal José-Antonio JA Álvarez Rosario R Díaz Isabel I García-Mauriño Sofía S Echevarría Cristina C

Frontiers in plant science 20190509

Phosphoenolpyruvate carboxylase (PEPC) is a cytosolic, homotetrameric enzyme that serves a variety of functions in plants, acting as the primary form of CO2 fixation in the C4 photosynthesis pathway (C4-PEPC). In a previous work we have shown that C4-PEPC bind anionic phospholipids, resulting in PEPC inactivation. Also, we showed that PEPC can associate with membranes and to be partially proteolyzed. However, the mechanism controlling this remains unkn ...[more]

PMID: 31143196

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Project description:Phosphoenolpyruvate carboxylase (PEPC) is an important enzyme in plants, which regulates carbon flow through the TCA cycle and controls protein and oil biosynthesis. Although it is important, there is little research on PEPC in cotton, the most important fiber crop in the world. In this study, a total of 125 PEPCs were identified in 15 Gossypium genomes. All PEPC genes in cotton are divided into six groups and each group generally contains one PEPC member in each diploid cotton and two in each tetraploid cotton. This suggests that PEPC genes already existed in cotton before their divergence. There are additional PEPC sub-groups in other plant species, suggesting the different evolution and natural selection during different plant evolution. PEPC genes were independently evolved in each cotton sub-genome. During cotton domestication and evolution, certain PEPC genes were lost and new ones were born to face the new environmental changes and human being needs. The comprehensive analysis of collinearity events and selection pressure shows that genome-wide duplication and fragment duplication are the main methods for the expansion of the PEPC family, and they continue to undergo purification selection during the evolutionary process. PEPC genes were widely expressed with temporal and spatial patterns. The expression patterns of PEPC genes were similar in G. hirsutum and G. barbadense with a slight difference. PEPC2A and 2D were highly expressed in cotton reproductive tissues, including ovule and fiber at all tested developmental stages in both cultivated cottons. However, PEPC1A and 1D were dominantly expressed in vegetative tissues. Abiotic stress also induced the aberrant expression of PEPC genes, in which PEPC1 was induced by both chilling and salinity stresses while PEPC5 was induced by chilling and drought stresses. Each pair (A and D) of PEPC genes showed the similar response to cotton development and different abiotic stress, suggesting the similar function of these PEPCs no matter their origination from A or D sub-genome. However, some divergence was also observed among their origination, such as PEPC5D was induced but PEPC5A was inhibited in G. barbadense during drought treatment, suggesting that a different organized PEPC gene may evolve different functions during cotton evolution. During cotton polyploidization, the homologues genes may refunction and play different roles in different situations.

Dataset Information

Anionic Phospholipids Induce Conformational Changes in Phosphoenolpyruvate Carboxylase to Increase Sensitivity to Cathepsin Proteases.

Publications

Anionic Phospholipids Induce Conformational Changes in Phosphoenolpyruvate Carboxylase to Increase Sensitivity to Cathepsin Proteases.

Similar Datasets

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