Related Experiment Video
Updated: Aug 11, 2026

Using Microtiter Dish Radiolabeling for Multiple In Vivo Measurements Of Escherichia coli (p)ppGpp Followed by Thin Layer Chromatography
Published on: June 4, 2019
Protein phosphatase inhibitor-1 (PPI-1) has protective activities in stress conditions in E. coli
1Department of Biological and Molecular Engineering, College of Engineering, Ajou University, Suwon 443-749, South Korea. doohunkim@ajou.ac.kr
Abstract:
Protein phosphatase inhibitor-1 (PPI-1) is a major inhibitor of protein phosphatase 1 (PP1), which regulates signal transduction in many eukaryotic cellular processes. Biophysical studies have shown that PPI-1 has a large Stokes radius and is heat stable, suggesting that it lacks extensive secondary structures. The unfolded structure of PPI-1 may enable it to interact with many proteins or ligands during stress conditions. Here we show that PPI-1 can act as a protective molecule, inhibiting protein aggregation and guarding E. coli cells against various stresses. Therefore, PPI-1 seems to have a physiological function as a protective molecule as well as regulator of protein serine/threonine phosphatases.
Related Concept Videos
Other Stress Responses in Bacteria
Stringent Response in E. coli
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Regulation of the Unfolded Protein Response
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein.
Negative Regulator Molecules

