Related Experiment Video
Updated: Sep 27, 2026

Cell-Type Specific Protein Purification and Identification from Complex Tissues Using a Mutant Methionine tRNA Synthetase Mouse Line
Published on: April 13, 2022
A kinetic proof-reading mechanism for protein sorting
Matthias Weiss1, Tommy Nilsson
1Cell Biology and Cell Biophysics Programme, EMBL, Meyerhofstrasse 1, D-69117 Heidelberg, Germany. mweiss@embl-heidelberg.de
Abstract:
Resident proteins of the exocytic pathway are maintained at various levels through coatomer protein I (COPI)-mediated recycling. Sorting of cargo by COPI requires GTP hydrolysis by ADP-ribosylation factor 1 (ARF-1). This small GTPase recruits coatomer onto Golgi membranes and upon hydrolysis, is thought to release coatomer back into the cytosol. This step requires the activating protein, ARFGAP1. By coupling sorting to a cargo-induced sequestering of ARFGAP1, we have formulated a kinetic proof-reading model that explains how a GTP hydrolysis-driven coat release can yield an active sorting event. The sorting scheme predicts a dependency on the amount of ARFGAP1 and explains the recent experimental findings that ARF-1 and COPI detach with different time constants from the Golgi membrane in vivo.
Related Concept Videos
Overview of Protein Sorting and Transport
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
Mitochondrial Protein Sorting
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Signal Sequences and Sorting Receptors
Directing Proteins to the Rough Endoplasmic Reticulum
Nuclear Protein Sorting
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Protein Folding Quality Check in the RER

