Work

N-Acetyl-L-glutamate Kinase of Chlamydomonas reinhardtii: In Vivo Regulation by PII Protein and Beyond

Year: 2023

Type: article

Abstract: N-Acetyl-L-glutamate kinase (NAGK) catalyzes the rate-limiting step in the ornithine/arginine biosynthesis pathway in eukaryotic and bacterial oxygenic phototrophs. NAGK is the most highly conserved target of the PII signal transduction protein in Cyanobacteria and Archaeplastida (red algae and Chlorophyta). However, yet there is still much to be learnt on how NAGK is regulated in vivo. The use of unicellular green Chlamydomonas reinhardtii as a model system has already been instrumental in identifying several key regulation mechanisms that control nitrogen (N) metabolism. With a combination of molecular-genetic and biochemical approaches, we show the existence of the complex CrNAGK control at transcriptional level, which is dependent on N source and N availability. In growing cells, CrNAGK requires CrPII to properly sense the feedback inhibitor arginine. Moreover, we provided primary evidence that CrPII is only partly responsible for regulating CrNAGK activity to adapt to changing nutritional conditions. Collectively, our results suggest that in vivo CrNAGK is tuned at transcriptional and post-translational levels, and CrPII and additional as yet unknown factor(s) are integral parts of this regulation.

Source: International Journal of Molecular Sciences

DOI: 10.3390/ijms241612873

Authors: Vitalina Vlasova, Tatiana Lapina, Vladislav Statinov, Elena Ermilova

Institution: St Petersburg University

Language: English

Topic: Plant nutrient uptake and metabolism

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $2,780

Funders: Russian Science Foundation, Universidad de Córdoba