FNTB Gene (Farnesyltransferase, CAAX Box, Beta Subunit)
A key enzyme in protein prenylation, implicated in cancer and progeria syndromes.
Gene Information Card
| Symbol | FNTB |
|---|---|
| Full Name | Farnesyltransferase, CAAX Box, Beta Subunit |
| Gene Type | Protein coding |
| Chromosomal Location | 14q23.3 |
| NCBI Gene ID | 2342 ncbi.nlm.nih.gov/gene/2342 |
| Ensembl ID | ENSG00000100804 |
| UniProt ID | P49356 |
| OMIM ID | 134635 |
| HGNC ID | 3785 |
| Aliases | FTase-beta, FPTB, PTAR2 |
Description
The FNTB gene encodes the beta subunit of farnesyltransferase, a heterodimeric enzyme that catalyzes the addition of a farnesyl group to the cysteine residue of CAAX motif-containing proteins. This prenylation is essential for the membrane localization and function of many proteins, including members of the RAS superfamily. FNTB is a target for anticancer drug development, particularly in RAS-driven tumors.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hutchinson-Gilford Progeria Syndrome | Mutations in LMNA produce a permanently farnesylated prelamin A; FNTB inhibition reduces progerin toxicity. | ClinVar, OMIM |
| Various Cancers (e.g., lung, pancreatic, colon) | Overexpression or altered splicing of FNTB enhances farnesylation of oncogenic RAS, promoting tumor growth. | COSMIC, NCBI Gene |
| Myelodysplastic Syndrome | FNTB mutations or copy number alterations may contribute to dysregulated prenylation in hematopoietic cells. | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Adrenal Gland | 9.8 | Medium |
| Pancreas | 8.2 | Medium |
| Liver | 6.1 | Low |
| Brain | 4.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa (cervical carcinoma) | 10.2 | High expression |
| A549 (lung carcinoma) | 9.5 | High expression |
| MCF7 (breast carcinoma) | 7.8 | Medium expression |
| K562 (leukemia) | 6.4 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1096G>A (p.Gly366Arg) | Missense | <0.1% | Altered substrate binding affinity |
| c.1243C>T (p.Arg415Trp) | Missense | <0.1% | Potential loss of catalytic activity |
| c.1472_1473insA | Frameshift | <0.1% | Truncated protein, likely loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that produce truncated or unstable FNTB protein, reducing farnesyltransferase activity.
Gain of Function (GOF)
Not well documented; some missense variants may increase catalytic efficiency but are rare.
Dominant Negative (DN)
Not reported for FNTB.
View complete mutation data：
Gene Ontology (GO)
| • protein farnesyltransferase activity (GO:0004660) | • farnesyltransferase complex (GO:0005960) |
| • protein farnesylation (GO:0018342) | • nucleus (GO:0005634) |
| • cytoplasm (GO:0005737) |
Pathways
• Protein Prenylation (R-HSA-8873719)
• Signaling by RAS mutants (R-HSA-6802949)
• Farnesylation of RAS (R-HSA-9649945)
Protein Summary
FNTB encodes the 437-amino-acid beta subunit of farnesyltransferase. The enzyme is a zinc metalloprotein that, together with the alpha subunit (FNTA), transfers a farnesyl moiety from farnesyl diphosphate to the cysteine of CAAX motifs. The beta subunit determines substrate specificity. FNTB is ubiquitously expressed with highest levels in testis and adrenal gland. Inhibition of FNTB is a therapeutic strategy for progeria and RAS-mutant cancers.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CHURC1-FNTB Knockout HEK293 Cell Line | EDJ-KQ52500 | Human | 100529261 | Details Get a Quote |
| CHURC1-FNTB Knockout HeLa Cell Line | EDJ-KQ60963 | Human | 100529261 | Details Get a Quote |
| CHURC1-FNTB Knockout A-549 Cell Line | EDJ-KQ69438 | Human | 100529261 | Details Get a Quote |
| CHURC1-FNTB Knockout HCT 116 Cell Line | EDJ-KQ77789 | Human | 100529261 | Details Get a Quote |
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