IFT88: Intraflagellar Transport 88 – Ciliopathy and Cancer Gene
Essential component of the intraflagellar transport complex B, critical for cilia assembly and function; mutations cause ciliopathies and are implicated in cancer.
Gene Information Card
| Symbol | IFT88 |
|---|---|
| Full Name | Intraflagellar Transport 88 |
| Gene Type | Protein coding |
| Chromosomal Location | 13q12.1 |
| NCBI Gene ID | 8100 ncbi.nlm.nih.gov/gene/8100 |
| Ensembl ID | ENSG00000132780 |
| UniProt ID | Q13099 |
| OMIM ID | 600112 |
| HGNC ID | 5406 |
| Aliases | TG737, hTg737, polaris, D13S1056E, MKS13, NPHP18, RPGRIP1L-related |
Description
IFT88 encodes a subunit of the intraflagellar transport (IFT) complex B, which is essential for the assembly and maintenance of cilia. The protein is involved in anterograde transport of cargo along ciliary microtubules. Mutations in IFT88 cause ciliopathies including nephronophthisis, retinitis pigmentosa, and Meckel-Gruber syndrome. Altered expression is also linked to cancer progression.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Nephronophthisis 18 (NPHP18) | Loss-of-function mutations disrupt ciliary transport, leading to renal tubular degeneration | ClinVar, OMIM #600112 |
| Meckel-Gruber syndrome 13 (MKS13) | Biallelic IFT88 mutations impair ciliogenesis, causing developmental defects | OMIM #617562 |
| Retinitis pigmentosa (RP) | IFT88 defects compromise photoreceptor cilia, leading to retinal degeneration | ClinVar, PubMed |
| Polycystic kidney disease (PKD) | IFT88 hypomorphic alleles (e.g., Tg737orpk) cause cystic kidney disease in models | OMIM #600112, PubMed |
| Cancer (various) | IFT88 overexpression or loss alters cilia-dependent signaling (Hedgehog, Wnt) promoting tumorigenesis | COSMIC, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Kidney | 8.2 | Medium |
| Retina | 7.9 | Medium |
| Brain (cerebellum) | 6.1 | Low |
| Lung | 5.4 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 10.3 | Embryonic kidney cell line |
| HeLa | 7.8 | Cervical cancer cell line |
| HepG2 | 6.5 | Hepatocellular carcinoma cell line |
| A549 | 5.9 | Lung carcinoma cell line |
| MCF7 | 4.2 | Breast cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1882C>T (p.Arg628*) | Nonsense | Rare | Loss of function; truncation of IFT88 protein |
| c.1123G>A (p.Gly375Arg) | Missense | Rare | Impaired IFT complex B assembly |
| c.2542_2543del (p.Glu848fs) | Frameshift | Rare | Loss of function; associated with NPHP18 |
| c.1A>G (p.Met1?) | Start loss | Rare | No protein production; Meckel-Gruber syndrome |
Mutation functional classification
Loss of Function (LOF)
Most IFT88 disease mutations are loss-of-function (nonsense, frameshift, splice-site), leading to ciliary defects and ciliopathies.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported in IFT88.
Dominant Negative (DN)
Rare missense variants (e.g., p.Gly375Arg) may act as dominant-negative by disrupting IFT complex B assembly.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Intraflagellar transport (IFT) – KEGG: hsa04540
• Hedgehog signaling pathway – Reactome: R-HSA-5358351
• Ciliopathy-associated pathways – Reactome: R-HSA-5620924
Protein Summary
IFT88 is a 824-amino-acid protein (UniProt Q13099) that forms part of the IFT-B complex. It contains tetratricopeptide repeat (TPR) domains that mediate protein-protein interactions. The protein localizes to the basal body and ciliary axoneme, facilitating anterograde transport of ciliary components. Defects in IFT88 disrupt cilia formation and signaling, leading to multisystem disorders.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| IFT88 Knockout HEK293 Cell Line | EDJ-KQ6171 | Human | 8100 | Details Get a Quote |
| IFT88 Knockout A-549 Cell Line | EDJ-KQ29990 | Human | 8100 | Details Get a Quote |
| IFT88 Knockout HCT 116 Cell Line | EDJ-KQ29991 | Human | 8100 | Details Get a Quote |
| IFT88 Knockout HeLa Cell Line | EDJ-KQ29992 | Human | 8100 | Details Get a Quote |
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