Phosphatidylinositol 3-kinase regulatory subunit alpha (PIK3R1) is a 724-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P27986.
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The mean pLDDT of this model is 83.2 (confident overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.
| pLDDT band | Meaning | Share of residues |
|---|---|---|
| Above 90 | Very high: backbone and side chains are usually accurate | 50% |
| 70 to 90 | Confident: backbone generally right | 36% |
| 50 to 70 | Low: treat with caution | 4% |
| Below 50 | Very low: often disordered regions | 10% |
What pLDDT means and how to read it
Binds to activated (phosphorylated) protein-Tyr kinases, through its SH2 domain, and acts as an adapter, mediating the association of the p110 catalytic unit to the plasma membrane. Necessary for the insulin-stimulated increase in glucose uptake and glycogen synthesis in insulin-sensitive tissues. Plays an important role in signaling in response to FGFR1, FGFR2, FGFR3, FGFR4, KITLG/SCF, KIT, PDGFRA and PDGFRB. Likewise, plays a role in ITGB2 signaling (PubMed:17626883, PubMed:19805105, PubMed:7518429). Modulates the cellular response to ER stress by promoting nuclear translocation of XBP1 isoform 2 in a ER stress- and/or insulin-dependent manner during metabolic overloading in the liver…
Heterodimer of a regulatory subunit PIK3R1 and a p110 catalytic subunit (PIK3CA, PIK3CB or PIK3CD). Interacts (via SH2 domains) with CCDC88A/GIV (tyrosine-phosphorylated form); the interaction enables recruitment of PIK3R1 to the EGFR receptor, enhancing PI3K activity and cell migration (PubMed:21954290). Interacts (via SH2 domain) with CSF1R (tyrosine phosphorylated). Interacts with PIK3R2; the…
Cytoplasm
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 5GJI | X-ray | 0.9 Å | A=325-430 |
| 5AUL | X-ray | 1.1 Å | A=614-720 |
| 7CIO | X-ray | 1.1 Å | A=614-720 |
| 7RNS | X-ray | 1.14 Å | A=321-434 |
| 3I5R | X-ray | 1.7 Å | A=1-83 |
| 1H9O | X-ray | 1.79 Å | A=616-724 |
| 2IUG | X-ray | 1.89 Å | A=321-440 |
| 1PBW | X-ray | 2.0 Å | A/B=105-319 |
| 1PHT | X-ray | 2.0 Å | A=1-85 |
| 2IUH | X-ray | 2.0 Å | A=321-440 |
| 4JPS | X-ray | 2.2 Å | B=307-593 |
| 7PG5 | X-ray | 2.2 Å | B=307-593 |
| 6PYR | X-ray | 2.21 Å | B=431-599 |
| 8SBC | X-ray | 2.3 Å | B=306-593 |
| 4WAF | X-ray | 2.39 Å | B=306-617 |
| 2IUI | X-ray | 2.4 Å | A/B=321-440 |
| 2V1Y | X-ray | 2.4 Å | B=431-600 |
| 7TZ7 | X-ray | 2.41 Å | B=306-591 |
| 8DCP | EM | 2.41 Å | B=3-724 |
| 4L23 | X-ray | 2.5 Å | B=318-615 |
Showing 20 of 102 experimental structures (best resolution first).
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