GNAI1
G Protein Subunit Alpha i1
Gene Information Card
| Symbol | GNAI1 |
|---|---|
| Full Name | G Protein Subunit Alpha i1 |
| Gene Type | protein-coding |
| Chromosomal Location | 7q21.11 |
| NCBI Gene ID | 2770 ncbi.nlm.nih.gov/gene/2770 |
| Ensembl ID | ENSG00000127955 |
| UniProt ID | P63096 |
| OMIM ID | 139310 |
| HGNC ID | 4384 |
| Aliases | Gi, Gi alpha-1, GNAI1A, GNAI1B |
Description
GNAI1 encodes the alpha subunit of the heterotrimeric G protein Gi family. This subunit binds guanine nucleotides and mediates signal transduction from G protein-coupled receptors (GPCRs) to downstream effectors, inhibiting adenylyl cyclase activity. GNAI1 is involved in diverse cellular processes including cell proliferation, differentiation, and migration.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Altered GNAI1 expression may modulate GPCR signaling affecting tumor growth and metastasis | PMID: 25691885 |
| Colorectal cancer | GNAI1 mutations or expression changes linked to Wnt/β-catenin pathway dysregulation | PMID: 30093546 |
| Ovarian cancer | GNAI1 overexpression associated with poor prognosis and chemoresistance | PMID: 27626309 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Heart | 8.3 | Low |
| Liver | 4.1 | Low |
| Lung | 6.7 | Low |
| Kidney | 9.2 | Low |
| Testis | 15.8 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 10.2 | Embryonic kidney cell line |
| HeLa | 7.5 | Cervical cancer cell line |
| MCF7 | 14.1 | Breast cancer cell line |
| A549 | 6.8 | Lung cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.118G>A (p.Gly40Ser) | Missense | <0.1% | Altered GTP binding affinity |
| c.469C>T (p.Arg157Cys) | Missense | <0.1% | Reduced receptor coupling |
| c.1012A>G (p.Ile338Val) | Missense | <0.1% | Unknown functional effect |
Mutation functional classification
Loss of Function (LOF)
p.Gly40Ser reduces GTP binding and signaling
Gain of Function (GOF)
Not reported
Dominant Negative (DN)
Not reported
View complete mutation data：
Gene Ontology (GO)
| • G protein-coupled receptor signaling pathway | • adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway |
| • GTP binding | • GTPase activity |
| • signal transduction | • heterotrimeric G-protein complex |
Pathways
• GPCR downstream signaling
• cAMP signaling pathway
• G alpha (i) signalling events
Protein Summary
GNAI1 encodes the alpha-i1 subunit of heterotrimeric G proteins. The protein contains a guanine nucleotide-binding domain and intrinsic GTPase activity. Upon receptor activation, GNAI1 exchanges GDP for GTP, dissociates from beta-gamma subunits, and inhibits adenylyl cyclase, reducing cAMP levels. It is widely expressed with highest levels in brain and testis. Mutations are rare but may alter signaling in cancer.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GNAI1 Knockout HEK293 Cell Line | EDJ-KQ1316 | Human | 2770 | Details Get a Quote |
| GNAI1 Knockout HCT 116 Cell Line | EDJ-KQ19398 | Human | 2770 | Details Get a Quote |
| GNAI1 Knockout A-549 Cell Line | EDJ-KQ20741 | Human | 2770 | Details Get a Quote |
| GNAI1 Knockout HeLa Cell Line | EDJ-KQ20743 | Human | 2770 | Details Get a Quote |
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