Tuning of Pectin Methylesterification

Fabien F. Senechal (1) , Mélanie L’enfant (1) , Jean-Marc J.-M. Domon (1) , Emeline Rosiau (1) , Marie-Jeanne Crepeau (2) , Ogier Surcouf (3) , Juan Esquivel-Rodríguez (4) , Paulo Marcelo (5) , Alain A. Mareck (3) , Francois F. Guerineau (1) , Hyung-Rae Kim (6) , Jozef Mravec (7) , Estelle Bonnin (2) , Elisabeth Jamet (8) , Daisuke Kihara (4) , Patrice Lerouge (3) , Marie-Christine Ralet (2) , Jérome Pelloux (1) , Catherine C. Rayon (1)

1 BIOPI - Biologie des Plantes et Innovation - UR UPJV 3900
2 BIA - Unité de recherche sur les Biopolymères, Interactions Assemblages
3 Glyco-MEV - Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale
4 Department of Computer Science [Purdue]
5 ICAP - Plateforme d’Ingénierie Cellulaire et Analyses des Protéines (ICAP)
6 Purdue University [West Lafayette]
7 UCPH - University of Copenhagen = Københavns Universitet
8 Dynamique et Evolution des Parois cellulaires végétales

Pectin methylesterases (PMEs) catalyze the demethylesterification of homogalacturonan domains of pectin in plant cell walls and are regulated by endogenous pectin methylesterase inhibitors (PMEIs). In Arabidopsis dark-grown hypocotyls, one PME (AtPME3) and one PMEI (AtPMEI7) were identified as potential interacting proteins. Using RT-quantitative PCR analysis and gene promoter::GUS fusions, we first showed that AtPME3 and AtPMEI7 genes had overlapping patterns of expression in etiolated hypocotyls. The two proteins were identified in hypocotyl cell wall extracts by proteomics. To investigate the potential interaction between AtPME3 and AtPMEI7, both proteins were expressed in a heterologous system and purified by affinity chromatography. The activity of recombinant AtPME3 was characterized on homogalacturonans (HGs) with distinct degrees/patterns of methylesterification. AtPME3 showed the highest activity at pH 7.5 on HG substrates with a degree of methylesterification between 60 and 80% and a random distribution of methyl esters. On the best HG substrate, AtPME3 generates long non-methylesterified stretches and leaves short highly methylesterified zones, indicating that it acts as a processive enzyme. The recombinant AtPMEI7 and AtPME3 interaction reduces the level of demethylesterification of the HG substrate but does not inhibit the processivity of the enzyme. These data suggest that the AtPME3·AtPMEI7 complex is not covalently linked and could, depending on the pH, be alternately formed and dissociated. Docking analysis indicated that the inhibition of AtPME3 could occur via the interaction of AtPMEI7 with a PME ligand-binding cleft structure. All of these data indicate that AtPME3 and AtPMEI7 could be partners involved in the fine tuning of HG methylesterification during plant development.

Keywords: plant cell wall; protein expression; protein-protein interaction; plant biochemistry; homology modeling; gel diffusion assay; degree of blockiness; microscale thermophoresis; pectin methylesterase (PME); pectin methylesterase inhibitor (PMEI)

Domains: Chemical Sciences; Polymers; Life Sciences [q-bio]; Vegetal Biology; Plant breeding; Life Sciences [q-bio]; Development Biology; Gametogenesis; Life Sciences [q-bio]; Cellular Biology; Subcellular Processes [q-bio.SC]; Life Sciences [q-bio]; Cellular Biology; Cell Behavior [q-bio.CB]; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Biochemistry [q-bio.BM]; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Molecular biology; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Genomics [q-bio.GN]; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Molecular Networks [q-bio.MN]; Life Sciences [q-bio]; Vegetal Biology; Phytopathology and phytopharmacy; Life Sciences [q-bio]; Biotechnology

Fabien F. Senechal, Mélanie L’enfant, Jean-Marc J.-M. Domon, Emeline Rosiau, Marie-Jeanne Crepeau, et al.. Tuning of Pectin Methylesterification: pectin methylesterase inhibitor 7 modulates the processive activity of co-expressed pectin methylesterase 3 in a ph-dependent manner. Journal of Biological Chemistry, 2015, 290 (38), pp.23320 - 23335. ⟨10.1074/jbc.M115.639534⟩. ⟨hal-01841080⟩