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Arabidopsis PECTIN METHYLESTERASE17 is co-expressed with and processed by SBT3.5, a subtilisin-like serine protease.
- Source :
-
Annals of botany [Ann Bot] 2014 Oct; Vol. 114 (6), pp. 1161-75. Date of Electronic Publication: 2014 Mar 24. - Publication Year :
- 2014
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Abstract
- Background and Aims: In Arabidopsis thaliana, the degree of methylesterification (DM) of homogalacturonans (HGs), the main pectic constituent of the cell wall, can be modified by pectin methylesterases (PMEs). In all organisms, two types of protein structure have been reported for PMEs: group 1 and group 2. In group 2 PMEs, the active part (PME domain, Pfam01095) is preceded by an N-terminal extension (PRO part), which shows similarities to PME inhibitors (PMEI domain, Pfam04043). This PRO part mediates retention of unprocessed group 2 PMEs in the Golgi apparatus, thus regulating PME activity through a post-translational mechanism. This study investigated the roles of a subtilisin-type serine protease (SBT) in the processing of a PME isoform.<br />Methods: Using a combination of functional genomics, biochemistry and proteomic approaches, the role of a specific SBT in the processing of a group 2 PME was assessed together with its consequences for plant development.<br />Key Results: A group 2 PME, AtPME17 (At2g45220), was identified, which was highly co-expressed, both spatially and temporally, with AtSBT3.5 (At1g32940), a subtilisin-type serine protease (subtilase, SBT), during root development. PME activity was modified in roots of knockout mutants for both proteins with consequent effects on root growth. This suggested a role for SBT3.5 in the processing of PME17 in planta. Using transient expression in Nicotiana benthamiana, it was indeed shown that SBT3.5 can process PME17 at a specific single processing motif, releasing a mature isoform in the apoplasm.<br />Conclusions: By revealing the potential role of SBT3.5 in the processing of PME17, this study brings new evidence of the complexity of the regulation of PMEs in plants, and highlights the need for identifying specific PME-SBT pairs.<br /> (© The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Subjects :
- Amino Acid Sequence
Arabidopsis genetics
Arabidopsis Proteins metabolism
Carboxylic Ester Hydrolases metabolism
Cell Wall metabolism
Gene Knockout Techniques
Isoenzymes
Molecular Sequence Data
Mutation
Organ Specificity
Pectins metabolism
Plants, Genetically Modified
Promoter Regions, Genetic
Proteomics
Recombinant Fusion Proteins
Seedlings enzymology
Seedlings genetics
Subtilisins metabolism
Nicotiana enzymology
Nicotiana genetics
Arabidopsis enzymology
Arabidopsis Proteins genetics
Carboxylic Ester Hydrolases genetics
Gene Expression Regulation, Plant
Protein Processing, Post-Translational
Subtilisins genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1095-8290
- Volume :
- 114
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Annals of botany
- Publication Type :
- Academic Journal
- Accession number :
- 24665109
- Full Text :
- https://doi.org/10.1093/aob/mcu035