Related Experiment Video
Updated: Aug 17, 2026

PIP-on-a-chip: A Label-free Study of Protein-phosphoinositide Interactions
Published on: July 27, 2017
Reciprocally interacting domains of protein phosphatase 1 and focal adhesion kinase
Mariarita Bianchi1, Stefania De Lucchini, Michele Vietri
1Department of Experimental Pathology, University of Pisa, Pisa, Italy.
Abstract:
Protein phosphatase 1delta (PP1delta) localizes to focal adhesions and associates with the focal adhesion kinase (FAK). In the present work we used deletion mutants of PP1delta and FAK to detect their reciprocally interacting domains. Dissection of PP1delta indicated 194-260 as the shortest FAK-interacting domain among those tested. Domain 194-260 encompasses several sites involved in catalysis, indirectly confirming that FAK is a PP1 substrate. Mutation of one of these sites, R220 (R220S or R220Q), did not abolish but on the contrary increased the ability of 194-260 to pull-down FAK. Such property might be exploited to detect new potential PP1 substrates. Among the FAK deletion mutants, only the C-terminal domain (684-1053, also known as FRNK) pulled-down a significant amount of PP1. The PP1 eluted from a GST-FRNK affinity column displayed Mr of 35,000 when analyzed by gel-filtration on FPLC Superose 12, indicating the presence of an isolated PP1 catalytic subunit.
Related Concept Videos
Intracellular Signaling Affects Focal Adhesions
Some...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Amplifying Signals via Enzymatic Cascade
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
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...
The JAK-STAT Signaling Pathway

