PIK3CA
Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha
Gene Information Card
| Symbol | PIK3CA |
|---|---|
| Full Name | Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha |
| Gene Type | protein-coding |
| Chromosomal Location | 3q26.32 |
| NCBI Gene ID | 5290 ncbi.nlm.nih.gov/gene/5290 |
| Ensembl ID | ENSG00000121879 |
| UniProt ID | P42336 |
| OMIM ID | 171834 |
| HGNC ID | 8975 |
| Aliases | PI3K, p110-alpha, CLOVE, MCM, PI3K-alpha |
Description
PIK3CA encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K), a lipid kinase that phosphorylates phosphatidylinositol-4,5-bisphosphate (PIP2) to generate phosphatidylinositol-3,4,5-trisphosphate (PIP3). PIP3 acts as a second messenger activating downstream signaling pathways including AKT/mTOR, regulating cell growth, proliferation, survival, and metabolism. Activating mutations in PIK3CA are among the most common somatic alterations in human cancers and also cause postzygotic mosaic disorders such as PIK3CA-related overgrowth spectrum (PROS).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Activating hotspot mutations (e.g., E545K, H1047R) increase PI3K signaling, promoting uncontrolled proliferation and survival. | ClinVar, COSMIC |
| Colorectal cancer | Somatic gain-of-function mutations in PIK3CA activate the PI3K/AKT pathway, contributing to tumorigenesis. | COSMIC, NCBI |
| PIK3CA-related overgrowth spectrum (PROS) | Postzygotic activating mutations cause mosaic overgrowth of tissues, including CLOVES syndrome and megalencephaly-capillary malformation. | OMIM, ClinVar |
| Endometrial cancer | Frequent PIK3CA mutations (especially in exon 9 and 20) drive PI3K/AKT pathway activation. | COSMIC, NCBI |
| Ovarian cancer | Somatic PIK3CA mutations are common in clear cell and endometrioid subtypes, activating PI3K signaling. | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Breast | 12.2 nTPM | Medium |
| Colon | 8.5 nTPM | Medium |
| Lung | 6.3 nTPM | Low |
| Brain | 4.1 nTPM | Low |
| Liver | 3.8 nTPM | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MCF7 (breast cancer) | 15.0 nTPM | High expression |
| HCT116 (colorectal cancer) | 10.2 nTPM | Moderate expression |
| A549 (lung cancer) | 7.5 nTPM | Moderate expression |
| HEK293 (embryonic kidney) | 6.0 nTPM | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1624G>A (p.Glu542Lys) | Missense | ~15% in breast cancer | Gain-of-function; increases kinase activity and PIP3 production |
| c.1633G>A (p.Glu545Lys) | Missense | ~20% in breast cancer | Gain-of-function; constitutive activation of PI3K |
| c.3140A>G (p.His1047Arg) | Missense | ~25% in breast cancer | Gain-of-function; enhances membrane recruitment and activity |
| c.3140A>T (p.His1047Leu) | Missense | ~5% in colorectal cancer | Gain-of-function; similar to H1047R |
Mutation functional classification
Loss of Function (LOF)
Rare; some truncating mutations may reduce PI3K activity but are not well characterized.
Gain of Function (GOF)
Common hotspot mutations (E542K, E545K, H1047R) increase lipid kinase activity and downstream AKT signaling.
Dominant Negative (DN)
Not reported for PIK3CA.
View complete mutation data：
Gene Ontology (GO)
| • phosphatidylinositol 3-kinase activity | • phosphatidylinositol-3 |
| • 4 | • 5-trisphosphate biosynthetic process |
| • protein kinase B signaling | • cell proliferation |
| • cell migration | • apoptotic process |
Pathways
• PI3K/AKT signaling pathway
• mTOR signaling pathway
• EGFR tyrosine kinase inhibitor resistance
• Breast cancer pathway
• Colorectal cancer pathway
Protein Summary
PIK3CA encodes the p110α catalytic subunit of class IA PI3K. The protein contains an N-terminal adaptor-binding domain (ABD), a Ras-binding domain (RBD), a C2 domain, a helical domain, and a C-terminal kinase domain. Upon activation by receptor tyrosine kinases, p110α associates with p85 regulatory subunit and generates PIP3, recruiting AKT to the membrane for phosphorylation. Mutations in the helical (E542K, E545K) and kinase (H1047R) domains cause constitutive activation, driving oncogenic signaling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PIK3CA Knockout Hep-G2 Cell Line | EDJ-KQ40 | Human | 5290 | Details Get a Quote |
| PIK3CA Knockout HEK293 Cell Line | EDJ-KQ518 | Human | 5290 | Details Get a Quote |
| PIK3CA Knockout HeLa Cell Line | EDJ-KQ18331 | Human | 5290 | Details Get a Quote |
| PIK3CA Knockout HCT 116 Cell Line | EDJ-KQ18850 | Human | 5290 | Details Get a Quote |
| Pik3ca Knockout EO771 Cell Line | EDJ-KZ399 | Mouse | 18706 | Details Get a Quote |
| PIK3CA Knockout A-549 Cell Line | EDJ-KQ62634 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.G914R) Point Mutation in HAP1 Cell Line | EDC03362 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.H1047P) Point Mutation in HAP1 Cell Line | EDC03363 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.H1047L) Point Mutation in HAP1 Cell Line | EDC03364 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.E545A) Point Mutation in HAP1 Cell Line | EDC03639 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.C420R) Point Mutation in HAP1 Cell Line | EDC03640 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.E542K) Point Mutation in HAP1 Cell Line | EDC03641 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.E545K) Point Mutation in HAP1 Cell Line | EDC03642 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.E545G) Point Mutation in HAP1 Cell Line | EDC03643 | Human | 5290 | Details Get a Quote |
| PIK3CA (p.Q546K) Point Mutation in HAP1 Cell Line | EDC03644 | Human | 5290 | Details Get a Quote |
Displaying Records 1 To 15 Of 19 Records
