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Updated: Sep 28, 2025
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LERLIC-MS/MS for In-depth Characterization and Quantification of Glutamine and Asparagine Deamidation in Shotgun Proteomics
Published on: April 9, 2017
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Polyglutamylation: biology and analysis
Cristian I Ruse1, Hang Gyeong Chin2, Sriharsa Pradhan3
1Moderna Therapeutics, 200 Technology Square, Cambridge, MA, 02139, USA. Cristian.Ruse@modernatx.com.
Amino Acids
|March 31, 2022
Summary
Polyglutamylation, a posttranslational modification, involves adding glutamate chains to proteins like tubulin. Proteomics methods now enable large-scale detection of these modified peptides, revealing key sites in tubulin and other proteins.
Area of Science:
- Biochemistry
- Molecular Biology
- Proteomics
Background:
- Polyglutamylation is a posttranslational modification (PTM) involving glutamate addition to proteins by polyglutamylases.
- This modification is well-documented in microtubules, affecting α- and β-tubulin subunits.
- Recent research has elucidated catalytic mechanisms of glutamylation enzymes, particularly tubulin tyrosine ligase-like (TTLL) family.
Purpose of the Study:
- To review advancements in using proteomics for large-scale polyglutamylated peptide detection.
- To summarize the biology and analytical approaches for studying polyglutamylation.
- To highlight newly identified polyglutamylation sites and enzymes.
Main Methods:
- Utilizing nano-electrospray ionization (ESI) proteomic approaches for quantifiable site identification.
- Employing nano-liquid chromatography and tandem mass spectrometry (MS/MS) for characterization.
- Mapping variable length polyglutamylation using protein chemistry and proteomics.
Main Results:
- Identified quantifiable polyglutamylated sites in specific substrates.
- Characterized conjugated glutamylated peptides via MS/MS.
- Revealed major polyglutamylation sites at E445 in α-tubulin, E435 in β-tubulin, and E860 in SdeA.
Conclusions:
- Proteomics has significantly advanced the large-scale detection and analysis of polyglutamylated peptides.
- Polyglutamylation extends beyond tubulin, with enzymes like SidJ identified.
- Understanding polyglutamylation patterns is crucial for functional microtubule dynamics and cellular processes.
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