Related Experiment Video
Updated: Oct 9, 2025

Isolation of Whole Cell Protein Lysates from Mouse Facial Processes and Cultured Palatal Mesenchyme Cells for Phosphoprotein Analysis
Published on: April 1, 2022
Extracellular Signalling Modulates Scar/WAVE Complex Activity through Abi Phosphorylation
Shashi Prakash Singh1, Peter A Thomason1, Robert H Insall1,2
1CRUK Beatson Institute, Glasgow G61 1BD, UK.
Cell migration relies on the Scar/WAVE complex. In Dictyostelium, Abi subunit phosphorylation by extracellular signals fine-tunes pseudopod dynamics and cell speed after Scar/WAVE activation.
Area of Science:
- Cell Biology
- Biochemistry
- Molecular Biology
Background:
- The Scar/WAVE complex is essential for actin-based cell migration, controlling lamellipodia and pseudopodia formation.
- Regulation of the Scar/WAVE complex is a key determinant of cell motility.
Purpose of the Study:
- To investigate the role of Abi subunit phosphorylation in the Scar/WAVE complex during cell migration.
- To determine how extracellular signals modulate Scar/WAVE complex activity and pseudopod dynamics.
Main Methods:
- Phosphorylation analysis of the Abi subunit in Dictyostelium cells.
- Creation and analysis of unphosphorylatable and phosphomimetic Abi mutants.
- Assessment of chemotaxis, pseudopodia formation, and cell speed in mutant Dictyostelium.
Main Results:
- Abi, but not Scar, is phosphorylated in response to extracellular signaling, occurring after Scar/WAVE complex activation.
- Abi phosphorylation is influenced by environmental cues like cell-substrate adhesion and osmolarity.
- While not essential for Scar/WAVE activation, Abi phosphorylation affects pseudopod protrusion duration, altering cell speed. Unphosphorylatable Abi leads to faster migration.
Conclusions:
- Extracellular signals modulate cell migration by tuning Scar/WAVE complex behavior post-activation through Abi phosphorylation.
- Abi phosphorylation acts as a regulatory mechanism influencing pseudopod dynamics and overall cell motility, rather than initiating complex activation.
More Related Videos
09:32Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development
Published on: June 15, 2017
07:34The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions
Published on: February 16, 2017
Related Concept Videos
Intracellular Signaling Affects Focal Adhesions
Some...
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Amplifying Signals via Enzymatic Cascade
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
TGF - β Signaling Pathway
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...