GO:0070735 protein-glycine ligase activity

Protein-glycine ligase activity (GO:0070735) is a molecular function that attaches glycine to a glutamyl residue on a target protein in an ATP-dependent manner. This post-translational modification can alter protein stability, localization, or interactions, thereby influencing diverse cellular processes. The reaction is formally: ATP + glycine + L-glutamyl-[protein] = ADP + glycyl-L-glutamyl-[protein] + H+ + phosphate. Understanding this activity is crucial because it represents a distinct regulatory mechanism that can modulate protein function beyond canonical phosphorylation or ubiquitination. In Schizosaccharomyces pombe, the Polo-like kinase Plo1 is recruited to the spindle pole body, and its function in cell division depends on proper protein-glycine ligation. This highlights the importance of GO:0070735 in cell cycle control and cytoskeletal organization. Researchers studying this term can gain insights into fundamental cell biology and potential disease mechanisms.

GO:0070735 protein-glycine ligase activity is defined as the catalysis of the reaction: ATP + glycine + L-glutamyl-[protein] = ADP + glycyl-L-glutamyl-[protein] + H+ + phosphate. In other words, it is an enzyme activity that uses ATP to covalently link glycine to a glutamate side chain on a protein substrate, releasing ADP and phosphate. This activity is also known as protein glycylase activity.

Protein-glycine ligase activity is important because it introduces a reversible post-translational modification that can regulate protein function in cell division and beyond. In Schizosaccharomyces pombe, this activity is required for Plo1 kinase recruitment to the spindle pole body, a key step in mitosis. Dysregulation of such modifications may contribute to human diseases, including cancer and neurodegenerative disorders, making this activity a potential therapeutic target.

The following genes and proteins are associated with protein-glycine ligase activity or its downstream effects, based on published literature.

Protein-glycine ligase activity is regulated by the availability of ATP, glycine, and target proteins, as well as by upstream signaling pathways that control cell cycle progression. In Schizosaccharomyces pombe, the activity is coordinated with Plo1 kinase recruitment to the spindle pole body, ensuring proper timing of cell division. Dysregulation of these regulatory mechanisms can lead to cell cycle defects.

Dysregulation of protein-glycine ligase activity may contribute to cancer through altered cell cycle control, as the modification is required for proper mitosis. Loss of function could lead to genomic instability, a hallmark of cancer.

Aberrant protein-glycine ligation might promote protein misfolding or aggregation, which is a common feature of neurodegenerative diseases. However, direct evidence linking this activity to neurodegeneration is still limited.

Because the activity is essential for cell division, defects could cause developmental abnormalities. Further research is needed to establish causal links.

Ribo-seq can measure translation efficiency of genes involved in protein-glycine ligation, while RNA-seq reveals transcriptional changes upon knockout or overexpression. These methods help identify downstream targets and pathways.

Mass spectrometry-based proteomics can identify proteins carrying glycyl-glutamyl modifications, providing a global view of substrates. This is crucial for understanding the scope of the activity.

Fluorescence microscopy can visualize the localization of ligase enzymes and modified proteins, such as at the spindle pole body. Live-cell imaging reveals dynamics during cell division.

In vitro assays with purified enzymes and substrates can measure ligase activity and kinetics. These assays are essential for mechanistic studies.

Researchers studying protein-glycine ligase activity-related genes often need to determine whether a candidate gene is causally involved in cell division, disease, or specific signaling pathways. EDITGENE provides comprehensive CRISPR services to accelerate this discovery.

Protein-glycine ligase activity (GO:0070735) is a critical post-translational modification that regulates protein function and cell division. Understanding its mechanism and regulation can provide insights into diseases such as cancer and neurodegeneration. CRISPR-based models and advanced omics methods are essential tools for further exploration.