UBAP1: Ubiquitin Associated Protein 1
A component of the ESCRT-I complex involved in endosomal sorting and associated with hereditary spastic paraplegia and cancer.
Gene Information Card
| Symbol | UBAP1 |
|---|---|
| Full Name | Ubiquitin Associated Protein 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 9p13.3 |
| NCBI Gene ID | 51271 ncbi.nlm.nih.gov/gene/51271 |
| Ensembl ID | ENSG00000165029 |
| UniProt ID | Q9NZ09 |
| OMIM ID | 609787 |
| HGNC ID | 12461 |
| Aliases | UBAP, NAG4, UBAP-1 |
Description
UBAP1 (Ubiquitin Associated Protein 1) encodes a component of the ESCRT-I (Endosomal Sorting Complexes Required for Transport) complex. The protein contains a ubiquitin-associated (UBA) domain and is involved in the sorting of ubiquitinated membrane proteins into multivesicular bodies for lysosomal degradation. Mutations in UBAP1 are associated with autosomal dominant hereditary spastic paraplegia type 80 (SPG80) and have been implicated in various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hereditary Spastic Paraplegia 80 (SPG80) | Loss-of-function mutations in UBAP1 impair ESCRT-I function, leading to defective endosomal trafficking and neuronal degeneration. | ClinVar, OMIM |
| Prostate Cancer | UBAP1 is a target of the NAG4 gene fusion; altered expression may contribute to tumorigenesis. | COSMIC, NCBI |
| Lung Cancer | Somatic mutations and altered expression of UBAP1 have been reported in lung adenocarcinoma. | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Testis | 10.3 | Medium |
| Lung | 8.1 | Low |
| Prostate | 7.4 | Low |
| Liver | 6.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.0 | High expression |
| HeLa | 11.2 | Medium expression |
| A549 | 9.8 | Medium expression |
| PC3 | 7.5 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.106C>T (p.Arg36*) | Nonsense | Rare (0.01%) | Loss of function; associated with SPG80 |
| c.280_281del (p.Leu94fs) | Frameshift | Rare | Loss of function; associated with SPG80 |
| c.1A>G (p.Met1?) | Start loss | Rare | Loss of function; associated with SPG80 |
| c.500G>A (p.Arg167Gln) | Missense | 0.02% | Uncertain significance; reported in cancer |
Mutation functional classification
Loss of Function (LOF)
Nonsense, frameshift, and start-loss mutations in UBAP1 lead to truncated or absent protein, impairing ESCRT-I function and causing SPG80.
Gain of Function (GOF)
No gain-of-function mutations have been reported for UBAP1.
Dominant Negative (DN)
Some UBAP1 missense mutations may exert dominant-negative effects by disrupting ESCRT-I assembly, though evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • endosome (GO:0005768) | • ESCRT I complex (GO:0000813) |
| • protein transport (GO:0015031) | • ubiquitin-dependent protein catabolic process (GO:0043162) |
| • protein binding (GO:0005515) |
Pathways
• ESCRT-mediated multivesicular body sorting (Reactome: R-HSA-917729)
• Endosomal Sorting Complex Required for Transport (ESCRT) (KEGG: hsa04144)
Protein Summary
UBAP1 is a 502-amino acid protein (UniProt Q9NZ09) that localizes to endosomes and functions as a subunit of the ESCRT-I complex. It contains an N-terminal ubiquitin-associated (UBA) domain that binds ubiquitin, facilitating the recognition and sorting of ubiquitinated cargo into intraluminal vesicles. The protein is essential for proper endosomal trafficking and lysosomal degradation. Loss of UBAP1 function leads to accumulation of autophagic substrates and neuronal degeneration.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| UBAP1L Knockout HEK293 Cell Line | EDJ-KQ16001 | Human | 390595 | Details Get a Quote |
| UBAP1L Knockout HCT 116 Cell Line | EDJ-KQ47073 | Human | 390595 | Details Get a Quote |
| UBAP1L Knockout HeLa Cell Line | EDJ-KQ47074 | Human | 390595 | Details Get a Quote |
| UBAP1 Knockout HBE1 Cell Line | EDJ-KZ71 | Human | 51271 | Details Get a Quote |
| UBAP1 Knockout HEK293 Cell Line | EDJ-KQ51301 | Human | 51271 | Details Get a Quote |
| UBAP1 Knockout HeLa Cell Line | EDJ-KQ56267 | Human | 51271 | Details Get a Quote |
| UBAP1 Knockout A-549 Cell Line | EDJ-KQ64756 | Human | 51271 | Details Get a Quote |
| UBAP1L Knockout A-549 Cell Line | EDJ-KQ68645 | Human | 390595 | Details Get a Quote |
| UBAP1 Knockout HCT 116 Cell Line | EDJ-KQ73202 | Human | 51271 | Details Get a Quote |
