Post Translational Modifications (PTMs) | Complete Process | Lecture 13 | Dr. Muhammad Naveed

Post-Translational Modifications (PTMs):
Post-translational modifications (PTMs) are covalent modifications that occur after a protein has been synthesized, and they play a crucial role in regulating various aspects of protein function, localization, and activity. There are numerous types of PTMs, and proteins can undergo multiple modifications simultaneously. Here are some common post-translational modifications of proteins:

1. Phosphorylation:
Process: Addition of a phosphate group to serine, threonine, or tyrosine residues.
Function: Regulates protein activity, cellular signaling, and enzyme function.

2. Glycosylation:
Process: Addition of sugar moieties (oligosaccharides) to asparagine (N-linked) or serine/threonine (O-linked) residues.
Function: Influences protein folding, stability, and recognition. Important for cell adhesion and signaling.

3. Acetylation:
Process: Addition of an acetyl group to lysine residues.
Function: Regulates chromatin structure, gene expression, and protein stability.

4. Methylation:
Process: Addition of a methyl group to lysine or arginine residues.
Function: Involved in gene expression, histone modification, and protein-protein interactions.

5. Ubiquitination:
Process: Attachment of ubiquitin molecules to lysine residues.
Function: Marks proteins for degradation by the proteasome, regulates protein levels, and controls various cellular processes.

6. Sumoylation:
Process: Attachment of small ubiquitin-like modifier (SUMO) proteins to lysine residues.
Function: Modulates protein localization, stability, and interactions. Often involved in nuclear-cytoplasmic shuttling.

7. Oxidation:
Process: Addition of oxygen to methionine, cysteine, or tryptophan residues.
Function: Can alter protein conformation, activity, and stability. Involved in redox signaling.

8. Proteolytic Cleavage:
Process: Removal of specific peptide segments from a protein.
Function: Activates or inactivates proteins, as seen in the activation of digestive enzymes or blood clotting factors.

9. Prenylation:
Process: Addition of lipid groups (farnesyl or geranylgeranyl) to cysteine residues.
Function: Facilitates protein membrane association and cellular localization.

10. ADP-Ribosylation:
Process: Addition of ADP-ribose moieties to specific amino acids.
Function: Involved in DNA repair, signaling, and regulation of various cellular processes.
These modifications often work in concert, creating a complex regulatory network that finely tunes cellular activities. Dysregulation of post-translational modifications is associated with various diseases, including cancer, neurodegenerative disorders, and metabolic diseases.

About Dr. Muhammad Naveed
(HoD, Biotechnology, University of Central Punjab, Lahore)

With distinction, Dr. Muhammad Naveed obtained a Ph.D. degree in Biotechnology (Genomics & Bioinformatics) from Quaid-e-Azam University, Islamabad. He has won Ph.D. indigenous & IRSIP scholarships from HEC. He has done Pre-Doc research at the University of Ghent, Belgium. HEC awarded him the best Ph.D. (IRSIP) Scholar of the Year in 2013 & QAU honored him as a “Distinguished Alumni” in 2017. He is doing research projects in Bioinformatics, Molecular Biotechnology and vaccine designing, and Drug designing against infectious diseases. He has supervised 90 MSc. and 78 MPhil. & 01 Ph.D. students. He has published 150 Research articles with 1120 impact factors, 5560 citations, 01 book, 06 book chapters, and filed 05 Patents. He was awarded the distinguished “Researcher of the Year” in 2016 (UoG) and 2018, 2019 & 2021 (UCP).

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