Our previous investigation revealed that GDP-Man pyrophosphorylase (VTC1), a vital ascorbic acid (AsA) biosynthesis enzyme, could be degraded through interaction with the photomorphogenic factor COP9 signalosome subunit 5B (CSN5B) in the darkness, demonstrating the posttranscriptional regulation of light signal in AsA production. Here, we further report that a point mutation in D27E of VTC1 disables the interaction with CSN5B, resulting in enhancement of AsA biosynthesis and seedling growth in Arabidopsis thaliana. To identify the interaction sites with CSN5B, we first predicted the key amino acids in VTC1 via bioinformatics analysis. And then we biochemically and genetically demonstrated that the 27th Asp was the amino acid that influenced the interaction of VTC1 with CSN5B in plants. Moreover, transgenic lines overexpressing the site-specific mutagenesis from D27 (Asp) into E27 (Glu) in VTC1 showed enhanced AsA accumulation and reduced H2O2 content in Arabidopsis seedlings, compared with the lines overexpressing the mutation from D27 into N27 (Asn) in VTC1. In addition, this regulation of VTC1 D27E mutation promoted seedling growth. Together, our data reveal that the 27th amino acid of VTC1 confers a key regulation in the interaction with CSN5B and AsA biosynthesis, as well as in Arabidopsis seedling growth.
Plant Molecular Biology – Springer Journals
Published: Aug 25, 2016
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud