Post-translational Modifications in Crop Improvement
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Post-translational modifications (PTMs) are chemical changes that occur to proteins after translation. PTMs play an important role in increasing the functional diversity of proteins by altering properties like activity, localization, and stability. Common PTMs include phosphorylation, glycosylation, ubiquitination, and methylation. These modifications influence many cellular processes and are critical for understanding diseases and improving crops through stress tolerance. PTMs are regulated by enzymes and can affect signaling, metabolism, and stress response pathways in plants.
Post-translational Modifications in Crop Improvement
- 3. Proteomics is the study of proteins on a genome-wide scale. Analyze protein features. Scope of Proteomics research Critical to understand
- 4. “Post-translational Modifications is the Chemical Modification of Protein after its Translation” OR “The Chemical Modification that takes place at certain amino acids residues after the protein is synthesized by translation” PTMs increases the functional diversity of the proteome by Covalent addition of functional groups to proteins Proteolytic cleavage of regulatory subunits, Degradation of entire proteins, Altering protein functions (Stabilizing and localizing) by binding to amino acids
- 5. “Post-translational Modifications is the Chemical Modification of Protein after its Translation” OR “The Chemical Modification that takes place at certain amino acids residues after the protein is synthesized by translation” PTMS occur mostly in E.R and golgi apparatus. Stability of protein Biochemical activity (activity regulation) Protein targeting (protein localization) Protein signaling (protein-protein interaction)
- 6. Post-translational modification Modification Involving Peptide Bonds Modification of amino acids Subunit aggregation Protein folding and chaperones 6 Protein Splicing
- 7. These modifications include: Phosphorylation Glycosylation Ubiquitination Nitrosylation Methylation Acetylation Lipidation Proteolysis Ref: Google images
- 8. Influence all aspects of cell biology Identifying and understanding PTMs is critical in: Study of cell biology Disease treatment Prevention Crop Improvement Cell response to stress
- 9. Can occur at any Step in life Cycle Tagging of Target Protein Mono-modification or Poly-modification Modulation of Stress Related genes Formation of Transgenic plants over-expressing regulators of Stress Response Improves tolerance to single or multiple stress factors.
- 10. Metal Stress Flooding Stress Chill Stress Heat Stress Water Stress Some Biotic Factors Ref: Google Images
- 11. One of Most ordinary Mechanism Mediated by “Kinase” Reversible protein modification It effects following aspects of Protein Function: Catalytic activity Subcellular localization, Stability Interaction with other proteins
- 12. Phosphorylation depends upon kinase and phosphatase activities acting on proteins Phosphatases are classified by their substrate preferences as Serine/Threonine, Tyrosine. The Serine/Threonine subclass is associated with low temperature signaling and the regulation of cold stress response. The inhibition of Serine/Threonine phosphatase activity induces cold-responsive genes in different species, including Arabidopsis, alfalfa, potato and tomato. PP2A
- 13. MAPKs CDPKs CIPKs RLPKs ACS6 ZAT10 TMT1 Dehydrins Ref: Google Images
- 14. Protein phosphorylation affects Metabolism The cell cycle, Stress, Hormonal responses, Stomatal closure Apoptosis Signal transduction pathways. Pathogen response, for example, plant–pathogen interactions, gene expression, and defense signaling in plants.
- 15. Ubiquitin is a small polypeptide attached to a lysine residue Tagging of proteins Process Action of three enzymes: Ubiquitin activating enzyme (E1) Ubiquitin conjugating enzyme (E2) Ubiquitin ligase (E3). 26S proteasome, a multisubunit ATP-dependent protease Ref: Google Images
- 16. 1400 genes in the Arabidopsis genome encoding E3 ubiquitin ligases Abiotic stresses alter the expression of more than 500 E3-ubiquitin ligase genes, ubiquitin-dependent protein degradation in stress- related signalling and response mechanisms Flower buds of Arabidopsis plants carrying a mutation in the ASK1 gene. In ASK1, the impairment of the SCF ligase-mediated ubiquitination and the resulting accumulation of SCF targets allowed the identification of ubiquitination targets.
- 17. SUMOylation is another important type of post-translational modification in which SUMO (Small Ubiquitin-related Modifier), a small polypeptide very similar to ubiquitin, is covalently bound to a lysine residue of a target protein. Same Enzymes except “SUMO needs to be proteolytically processed by the Sentrin-specific Protease (SENPs) to expose the C-terminal”. Action of three enzymes: SUMO activating enzyme (E1) SUMO conjugating enzyme (E2) SUMO ligase (E3).
- 18. Sumoylation alters protein function Biological consequences of sumoylation are: Sub-cellular re-localization, Changes in enzymatic activity Response to environmental signals. Ref: Google Images
- 19. SIZ1 is one of the three E3 SUMO ligases encoded by the Arabidopsis genome Responsible for augmentation in SUMO conjugates The loss of function causes a reduction in cold-induced freezing tolerance.
- 20. SUMOylation is involved in: Transcriptional regulation, DNA repair, Nuclear transport, Mitochondrial fission Regulation of receptors at the plasma membrane. Arabidopsis SIZ1
- 21. Phosphorylation Glycosylation Acylation Alkylation Hydroxylation Pro, Lys Ser, Thr, Tyr Asn, Ser, Thr Asn, Gln, Lys Lys, Arg
- 22. Glycosylation can be N-linked or O-linked, which is determined by the transfer of glycosidase and glycosyl between the Golgi apparatus and the endoplasmic reticulum. Proteins at the endomembrane system N-glycosylation is involved in Stability, Activity and Subcellular localization of proteins. The N-glycosylation pattern of 22 rice proteins is modified, whose Arabidopsis homolog, named LOS2, is an important regulator of cold acclimation.
- 23. Acetylation and deacetylation in N-terminal and K- residue are suggested as rival to phosphorylation. Modify a variety of proteins including: Transcription factors, Nuclear factors Alpha-tubulin DNA recognition Protein-protein interaction Protein stability
- 24. The transfer of one-carbon methyl group of nitrogen or oxygen (N- and O-methylation, respectively) to amino acid side chains increases the hydrophobicity of the protein and can neutralize a negative amino acid charge when bound to carboxylic acids. Methylation is mediated by methyl-transferases, and S- adenosyl methionine (SAM) is the primary methyl group donor.
- 25. Ref: Proteome changes for crop improvement
- 26. Post-Translational Modifications of Nuclear Proteins in the Response of Plant Cells to Abiotic Stresses REVIEW: Post-translational 1 regulation of cold acclimation response Co- and post-translational modifications in Rubisco Genomics and Bioinformatics Resources for Crop Improvement
- 27. Functional Proteomics of Arabidopsis thaliana Guard Cells Uncovers New Stomatal Signaling Pathways Advances in Proteomics and Bioinformatics in Agriculture Research and Crop Improvement Abiotic stress response in plants: When post- transcriptional and post-translational regulations control transcription Proteome changes for crop improvement