Redox activity of thioredoxin z and fructokinase-like protein 1 is dispensable for autotrophic growth of Arabidopsis thaliana
- Redox modulation of protein activity by thioredoxins (TRXs) plays a key role in cellular regulation. Thioredoxin z (TRX z) and its interaction partner fructokinase-like protein 1 (FLN1) represent subunits of the plastid-encoded RNA polymerase (PEP), suggesting a role of both proteins in redox regulation of chloroplast gene expression. Loss of TRX z or FLN1 expression generates a PEP-deficient phenotype and renders the plants incapable to grow autotrophically. This study shows that PEP function in trx z and fln1 plants can be restored by complementation with redox-inactive TRX z C106S and FLN1 C(105/106)A protein variants, respectively. The complemented plants showed wild-type levels of chloroplast gene expression and were restored in photosynthetic capacity, indicating that redox regulation of PEP through TRX z/FLN1 per se is not essential for autotrophic growth. Promoter-reporter gene studies indicate that TRX z and FLN1 are expressed during early phases of leaf development while expression ceases at maturation. Taken together, ourRedox modulation of protein activity by thioredoxins (TRXs) plays a key role in cellular regulation. Thioredoxin z (TRX z) and its interaction partner fructokinase-like protein 1 (FLN1) represent subunits of the plastid-encoded RNA polymerase (PEP), suggesting a role of both proteins in redox regulation of chloroplast gene expression. Loss of TRX z or FLN1 expression generates a PEP-deficient phenotype and renders the plants incapable to grow autotrophically. This study shows that PEP function in trx z and fln1 plants can be restored by complementation with redox-inactive TRX z C106S and FLN1 C(105/106)A protein variants, respectively. The complemented plants showed wild-type levels of chloroplast gene expression and were restored in photosynthetic capacity, indicating that redox regulation of PEP through TRX z/FLN1 per se is not essential for autotrophic growth. Promoter-reporter gene studies indicate that TRX z and FLN1 are expressed during early phases of leaf development while expression ceases at maturation. Taken together, our data support a model in which TRX z and FLN1 are essential structural components of the PEP complex and their redox activity might only play a role in the fine tuning of PEP function.…
Author details: | Matthias Wimmelbacher, Frederik BörnkeORCiDGND |
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DOI: | https://doi.org/10.1093/jxb/eru122 |
ISSN: | 0022-0957 |
ISSN: | 1460-2431 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/24659486 |
Title of parent work (English): | Journal of experimental botany |
Publisher: | Oxford Univ. Press |
Place of publishing: | Oxford |
Publication type: | Article |
Language: | English |
Year of first publication: | 2014 |
Publication year: | 2014 |
Release date: | 2017/03/27 |
Tag: | Chloroplast transcription; FLN1; TRX z; plastid-encoded RNA polymerase; redox regulation; thioredoxins |
Volume: | 65 |
Issue: | 9 |
Number of pages: | 9 |
First page: | 2405 |
Last Page: | 2413 |
Funding institution: | Deutsche Forschungsgemeinschaft [BO1916/3-1] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie |
Peer review: | Referiert |