USP44: Ubiquitin Specific Peptidase 44
A deubiquitinating enzyme involved in mitotic checkpoint control and tumor suppression
Gene Information Card
| Symbol | USP44 |
|---|---|
| Full Name | Ubiquitin Specific Peptidase 44 |
| Gene Type | Protein coding |
| Chromosomal Location | 12q22 |
| NCBI Gene ID | 84101 ncbi.nlm.nih.gov/gene/84101 |
| Ensembl ID | ENSG00000136014 |
| UniProt ID | Q9H0E7 |
| OMIM ID | 610993 |
| HGNC ID | 20064 |
| Aliases | USP44, Deubiquitinating enzyme 44 |
Description
USP44 (Ubiquitin Specific Peptidase 44) encodes a deubiquitinating enzyme that removes ubiquitin from target proteins, playing a critical role in the spindle assembly checkpoint (SAC) by deubiquitinating and stabilizing CDC20. It acts as a tumor suppressor by preventing aneuploidy and is frequently silenced or mutated in various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Loss of USP44 expression leads to mitotic checkpoint defects and aneuploidy | PMID: 20010870 |
| Colorectal cancer | Promoter hypermethylation and reduced USP44 expression correlate with chromosomal instability | PMID: 25242043 |
| Lung cancer | USP44 downregulation promotes tumor cell proliferation and invasion | PMID: 29065170 |
| Gastric cancer | USP44 mutations and low expression associated with poor prognosis | PMID: 30150777 |
| Prostate cancer | USP44 loss contributes to genomic instability and disease progression | PMID: 31570780 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 15.2 | Medium |
| Lymph node | 10.8 | Medium |
| Spleen | 9.5 | Medium |
| Bone marrow | 8.3 | Low |
| Brain | 4.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 12.5 | Embryonic kidney |
| HeLa | 9.8 | Cervical carcinoma |
| MCF7 | 7.2 | Breast cancer |
| A549 | 6.1 | Lung cancer |
| HCT116 | 5.4 | Colorectal cancer |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1015C>T (p.Arg339*) | Nonsense | <0.1% | Loss of function |
| c.1234G>A (p.Gly412Arg) | Missense | <0.1% | Unknown |
| c.789_790insA (p.Leu264fs) | Frameshift | <0.1% | Loss of function |
| c.1456C>T (p.Pro486Ser) | Missense | <0.1% | Unknown |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations (e.g., p.Arg339*, p.Leu264fs) result in truncated or non-functional protein, impairing mitotic checkpoint control.
Gain of Function (GOF)
No gain-of-function mutations reported in USP44.
Dominant Negative (DN)
No dominant-negative mutations reported in USP44.
View complete mutation data：
Gene Ontology (GO)
| • thiol-dependent deubiquitinase activity (GO:0004843) | • ubiquitin-dependent protein catabolic process (GO:0006511) |
| • mitotic spindle assembly checkpoint (GO:0007094) | • nucleus (GO:0005634) |
| • cytosol (GO:0005829) |
Pathways
• Cell Cycle
• Mitotic (Reactome: R-HSA-69278)
• Regulation of APC/C activators between G1/S and early anaphase (Reactome: R-HSA-176408)
Protein Summary
USP44 is a 712-amino acid deubiquitinating enzyme containing a catalytic USP domain. It specifically cleaves ubiquitin from CDC20, thereby stabilizing the mitotic checkpoint complex and preventing premature anaphase. Loss of USP44 function leads to aneuploidy and contributes to tumorigenesis. The protein is predominantly nuclear and expressed in testis, lymphoid tissues, and various cancer cell lines.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| USP44 Knockout HEK293 Cell Line | EDJ-KQ9980 | Human | 84101 | Details Get a Quote |
| USP44 Knockout HeLa Cell Line | EDJ-KQ57533 | Human | 84101 | Details Get a Quote |
| USP44 Knockout A-549 Cell Line | EDJ-KQ66031 | Human | 84101 | Details Get a Quote |
| USP44 Knockout HCT 116 Cell Line | EDJ-KQ74455 | Human | 84101 | Details Get a Quote |
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