AMPylation profiling during neuronal differentiation reveals extensive variation on lysosomal proteins

Area of Science:

• Biochemistry
• Neuroscience
• Cell Biology

Background:

• Protein AMPylation is an emerging posttranslational modification implicated in neurodevelopment.
• Its precise function and the localization of AMPylated proteins and AMP-transferases remain largely unknown.
• Identifying the cellular location and function of AMPylation is critical for understanding its role in neuronal processes.

Purpose of the Study:

• To investigate the cellular localization and functional significance of protein AMPylation in differentiating neurons.
• To identify specific AMPylated proteins and their associated enzymes within neuronal cells.
• To explore the potential link between AMPylation and neurodevelopmental disorders.

Main Methods:

• Chemical proteomics was employed to identify AMPylated proteins.
• Gel-based separation techniques were used to isolate modified and unmodified proteins.
• Biochemical assays, including activity assays, were performed to assess enzyme function.

Main Results:

• Protein AMPylation was identified as a posttranslational modification of luminal lysosomal proteins in differentiating neurons.
• The study found a significant increase in the modified, lysosomal soluble form of exonuclease PLD3 during neuronal maturation.
• AMPylation of PLD3 was observed to correlate with its catalytic activity.

Conclusions:

• AMPylation is a novel lysosomal posttranslational modification associated with neuronal differentiation.
• This modification is linked to the activity of lysosomal enzymes like PLD3.
• The findings may offer a molecular basis for understanding lysosomal storage diseases and neurodegeneration.