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Orphan PTMs: Rare, yet functionally important modifications of cysteine.
D Alexander Shannon1, Eranthie Weerapana
1Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, 02467.
Biopolymers
|April 9, 2013
Summary
Cysteine residues undergo rare post-translational modifications like phosphorylation, methylation, and ubiquitination. Despite their infrequent occurrence, these modifications are crucial for protein catalysis and regulation.
Area of Science:
- Biochemistry
- Molecular Biology
- Proteomics
Background:
- Cysteine residues possess a reactive thiol group, making them prone to various electrophilic and oxidative modifications.
- Well-characterized cysteine modifications include disulfide bonds, sulfenic acids, nitrosothiols, and lipid adducts.
- Less common modifications like phosphorylation, methylation, and ubiquitination also occur on cysteine residues.
Purpose of the Study:
- To detail rare post-translational modifications of cysteine.
- To describe the discovery and functional characterization of these modifications in various proteins.
- To highlight proteomic tools for identifying these modifications and understanding their biological significance.
Main Methods:
- Literature review of reported cysteine modifications.
- Analysis of functional characterization studies on modified proteins.
- Discussion of proteomic strategies for modification identification.
Main Results:
- Cysteine phosphorylation, methylation, and ubiquitination, though rare, are functionally significant.
- These modifications play critical roles in enzyme catalysis and cellular regulation.
- Diverse proteins have been identified with these less common cysteine modifications.
Conclusions:
- Rare post-translational modifications of cysteine are vital for biological processes.
- Further proteomic research is needed to fully map the landscape of these modifications.
- Understanding these modifications can provide new insights into protein function and regulation.
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