Assaying Arginylation Activity in Cell Lysates Using a Fluorescent Reporter.

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Background:

• Arginyltransferase1 (Ate1) is crucial for protein degradation and cellular regulation.
• Existing methods for assessing Ate1 enzymatic activity are limited.
• A reliable assay is needed to study Ate1 function in various biological contexts.

Purpose of the Study:

• To develop and validate a novel antibody-based assay for quantifying arginyltransferase1 (Ate1) enzymatic activity.
• To demonstrate the utility of this assay in analyzing Ate1 function under different conditions.

Main Methods:

• An antibody-based assay was established using a reporter protein with a beta-actin N-terminus and a C-terminal GFP tag.
• Arginylation levels were detected using an antibody specific to the arginylated N-terminus.
• Total substrate levels were measured using an anti-GFP antibody via immunoblotting.

Main Results:

• The developed assay accurately measures Ate1 enzymatic activity in both yeast and mammalian cell lysates.
• The method successfully determined the impact of mutations on critical Ate1 residues.
• The assay effectively evaluated the effects of stress and other factors on Ate1 activity.

Conclusions:

• This antibody-based method provides a convenient and accurate way to assess arginyltransferase1 (Ate1) enzymatic activity.
• The assay is versatile and applicable for studying Ate1 in various research settings, including mutation analysis and stress response studies.