Proteomic Characterization of the Heart and Skeletal Muscle Reveals Widespread Arginine ADP-Ribosylation by the ARTC1...

Area of Science:

• Biochemistry
• Molecular Biology
• Proteomics

Background:

• The ecto-ADP-ribosyltransferase ARTC1 has a restricted expression in skeletal muscle and heart.
• Identifying ARTC1 targets in vivo and understanding its regulated processes on a proteome level has been challenging.
• Only a limited number of ARTC1-ADP-ribosylated targets were previously known.

Purpose of the Study:

• To identify ARTC1-ADP-ribosylated proteins in skeletal muscle and heart tissue.
• To characterize ARTC1-regulated cellular processes on the proteome level.
• To validate ARTC1 targets and confirm the functional importance of ARTC1-mediated ADP-ribosylation.

Main Methods:

• Application of a newly developed mass spectrometry-based workflow.
• Analysis of C2C12 myotubes, skeletal muscle, and heart tissues from wild-type and ARTC1-deficient mice.
• Proteomic analysis to identify ADP-ribosylated proteins and their modification sites.

Main Results:

• Identification of hundreds of ARTC1-ADP-ribosylated proteins, absent in ARTC1-deficient mice.
• These proteins are modified on arginine residues and primarily located extracellularly or on the cell surface.
• Affected proteins are involved in signal transduction, transmembrane transport, and muscle function.
• Hemopexin (HPX) was validated as a key ARTC1 target, confirming functional significance.

Conclusions:

• The study significantly expands the known targets of ARTC1.
• ARTC1 plays a crucial role in regulating extracellular and cell surface proteins involved in muscle and signaling pathways.
• Extracellular arginine ADP-ribosylation by ARTC1 is functionally important at a systems level.