Understanding the Regulation of Phosphoinositide 3-Kinase p110δ by p85α
Author Information
Author(s): Burke John E., Vadas Oscar, Berndt Alex, Finegan Tara, Perisic Olga, Williams Roger L.
Primary Institution: Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK
Hypothesis
The study investigates the isoform-specific regulation of PI3K p110δ by the p85α regulatory subunit.
Conclusion
The cSH2 domain of p85α plays a crucial regulatory role in inhibiting p110δ, and its interaction with phosphorylated peptides enhances the enzyme's affinity for lipid membranes.
Supporting Evidence
- Both nSH2 and cSH2 of p85α inhibit p110δ, and pY peptides or mutations activate.
- DXMS mapped dynamic changes in free p110δ and p110δ/p85 with and without pY peptides.
- pY peptide increases p110δ/p85 affinity for lipids; interactions were mapped by DXMS.
- cSH2 point mutation in p85α activates p110δ and p110β, but not p110α.
Takeaway
This study shows how a protein called p85α helps control another protein, p110δ, which is important for cell signaling. When p85α changes, it can make p110δ work better.
Methodology
The study used deuterium exchange mass spectrometry (DXMS) to explore interactions between p110δ and p85α, along with lipid kinase assays to assess enzyme activity.
Digital Object Identifier (DOI)
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