Protein Phosphorylation in Chloroplasts

Lifeasible is committed to the development and research of chloroplast engineering. With years of experience in chloroplast proteomics, we are able to provide protein phosphorylation services in chloroplasts to change the physicochemical properties or enzymatic activities of chloroplast proteins, precisely meeting customer requirements.

Introduction

Phosphorylation is the most common protein post-translational modification (PTM) in plants by adding or removing one or more phosphate groups from the hydroxyl groups of specific serine (Ser), threonine (Thr) and tyrosine (Tyr) , thereby effectively changing the structure and activity of chloroplast proteins. Protein phosphorylation regulates metabolic and physiological pathways related to plant temperature stress, salt stress, drought stress, nutrient stress and hormone regulation under the synergistic action of protein kinases and phosphatases in the chloroplast. However, of all chloroplast phosphoproteins, 72% were identified as Ser phosphorylation and 27% as Thr phosphorylation, whereas Tyr phosphorylation has not been reliably detected to date. Therefore, phosphorylation of chloroplast proteins has been the target of intensive research. The study found that both the PSII core protein and the light-harvesting complex protein in the chloroplast can undergo reversible light-dependent phosphorylation. Phosphorylation of these proteins plays an important role in fine-tuning chloroplast metabolism.

Fig. 1. Major phosphoproteins of the thylakoid membrane in higher plants. (Longoni F P, et al., 2021)

Protein Phosphorylation in Chloroplasts Services

With the development of molecular biology, the rise of forward genetics in the model plant Arabidopsis thaliana, and the development of biochemistry, proteomics and structural biology, the study of plant protein phosphorylation has made important progress. Lifeasible is committed to the phosphoproteomic analysis of chloroplasts, including sequencing the phosphorylation site sequences and using mass spectrometry to identify chloroplast protein phosphorylation targets. In addition, we identified chloroplast phosphoproteins from whole-cell phosphoproteomic experiments by matching the identified phosphopeptides to proteins in the corresponding proteome reference table. We primarily performed phosphoproteomic analysis of the following chloroplast proteins:

· Thylakoid Membrane Protein Phosphorylation
Our scientists regulate photosynthetic light responses mainly by regulating PS II-related phosphorylated proteins, such as light-harvesting chlorophyll albumin and 4 proteins of the PS Ⅱ core.

· Phosphorylation of Calvin Cycle Enzymes
Our scientists achieved modulation of the photosynthetic light response by phosphorylating Calvin cycle enzymes, in conjunction with the regulation of the Calvin cycle as the main sink for photosynthetic electrons.

· Transcriptionally Active Chromosome (TAC) Phosphorylation
We achieved a long-term adaptive regulated light response by identifying phosphorylation sites in proteins associated with the transcriptional core of a transcriptionally active chromosome (TAC).

Applications of Chloroplasts Protein Phosphorylation

• Protein phosphorylation regulates photosynthesis.
• Protein phosphorylation regulates a novel pathway that integrates with metabolism and gene expression.
• Various chloroplast protein phosphorylation functions were identified.
• Mutants of the unicellular green alga Chlamydomonas reinhardtii were studied.

Lifeasible is committed to developing a variety of cutting-edge technologies to help customers around the world study different types of chloroplast protein modifications. We are proud to regulate plant growth and development, as well as control their pests, through chloroplast protein modifications. If you are interested in our services, please do not hesitate to contact us for more information.

References

1. Bennett J. (1991) Protein phosphorylation in green plant chloroplasts[J]. Annual review of plant biology. 42(1): 281-311.
2. Longoni F P, Goldschmidt-Clermont M. (2021) Thylakoid protein phosphorylation in chloroplasts[J]. Plant and Cell Physiology. 62(7): 1094-1107.