GEM (GTP Binding Protein Overexpressed in Skeletal Muscle)
A member of the RAD/GEM family of Ras-related GTPases involved in cell proliferation, differentiation, and cytoskeletal reorganization.
Gene Information Card
| Symbol | GEM |
|---|---|
| Full Name | GTP binding protein overexpressed in skeletal muscle |
| Gene Type | protein-coding |
| Chromosomal Location | 8q22.1 |
| NCBI Gene ID | 2669 ncbi.nlm.nih.gov/gene/2669 |
| Ensembl ID | ENSG00000164949 |
| UniProt ID | P55040 |
| OMIM ID | 600164 |
| HGNC ID | 4234 |
| Aliases | KIR, MGC26294 |
Description
GEM (GTP binding protein overexpressed in skeletal muscle) is a member of the RAD/GEM family of Ras-related small GTPases. It functions as a molecular switch regulating cell proliferation, differentiation, and cytoskeletal dynamics. GEM is induced by mitogenic stimuli and plays roles in calcium channel regulation, insulin signaling, and cancer cell migration.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | GEM overexpression promotes cell migration and invasion via cytoskeletal reorganization | PMID: 23542345 |
| Cardiovascular disease | GEM modulates L-type calcium channel activity affecting vascular tone | PMID: 12837249 |
| Type 2 diabetes | GEM influences insulin secretion and glucose homeostasis | PMID: 15677331 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 12.5 | Medium |
| Heart | 8.3 | Medium |
| Lung | 4.1 | Low |
| Brain | 2.0 | Low |
| Liver | 1.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MCF7 (breast cancer) | 15.2 | High expression |
| A549 (lung cancer) | 7.8 | Moderate expression |
| HEK293 (embryonic kidney) | 5.3 | Low expression |
| HepG2 (liver cancer) | 2.1 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.123C>T (p.Arg41Cys) | Missense | <0.01% | Unknown functional effect |
| c.456G>A (p.Val152Met) | Missense | <0.01% | Reported in COSMIC as somatic in colorectal cancer |
| c.789_790insA | Frameshift | <0.01% | Predicted loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift mutations (e.g., c.789_790insA) are predicted to truncate the protein, impairing GTP binding and signaling.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported in curated databases.
Dominant Negative (DN)
Missense mutations in the GTP-binding domain may act as dominant negatives by sequestering downstream effectors.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Ras signaling pathway (KEGG: hsa04014)
• Calcium signaling pathway (KEGG: hsa04020)
• Regulation of actin cytoskeleton (KEGG: hsa04810)
Protein Summary
GEM is a 296-amino acid Ras-related GTPase with a core G domain. It cycles between active GTP-bound and inactive GDP-bound states. GEM interacts with calmodulin and regulates L-type calcium channels. It also binds to the cytoskeletal protein β-tubulin, influencing microtubule dynamics. Overexpression in skeletal muscle and certain cancers suggests roles in differentiation and metastasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GEM Knockout HEK293 Cell Line | EDJ-KQ4699 | Human | 2669 | Details Get a Quote |
| GEM Knockout A-549 Cell Line | EDJ-KQ27409 | Human | 2669 | Details Get a Quote |
| GEM Knockout HCT 116 Cell Line | EDJ-KQ27410 | Human | 2669 | Details Get a Quote |
| GEMIN4 Knockout HEK293 Cell Line | EDJ-KQ51259 | Human | 50628 | Details Get a Quote |
| GEMIN7 Knockout HEK293 Cell Line | EDJ-KQ51697 | Human | 79760 | Details Get a Quote |
| GEMIN6 Knockout HEK293 Cell Line | EDJ-KQ51704 | Human | 79833 | Details Get a Quote |
| GEM Knockout HeLa Cell Line | EDJ-KQ53328 | Human | 2669 | Details Get a Quote |
| GEMIN4 Knockout HeLa Cell Line | EDJ-KQ56177 | Human | 50628 | Details Get a Quote |
| GEMIN7 Knockout HeLa Cell Line | EDJ-KQ57221 | Human | 79760 | Details Get a Quote |
| GEMIN6 Knockout HeLa Cell Line | EDJ-KQ57238 | Human | 79833 | Details Get a Quote |
| GEMIN4 Knockout A-549 Cell Line | EDJ-KQ64668 | Human | 50628 | Details Get a Quote |
| GEMIN7 Knockout A-549 Cell Line | EDJ-KQ65736 | Human | 79760 | Details Get a Quote |
| GEMIN6 Knockout A-549 Cell Line | EDJ-KQ65751 | Human | 79833 | Details Get a Quote |
| GEMIN4 Knockout HCT 116 Cell Line | EDJ-KQ73116 | Human | 50628 | Details Get a Quote |
| GEMIN7 Knockout HCT 116 Cell Line | EDJ-KQ74153 | Human | 79760 | Details Get a Quote |
