SYNJ2: Synaptojanin 2 - Gene and Protein Function
Comprehensive genomic and proteomic overview of SYNJ2, a phosphoinositide phosphatase involved in vesicle trafficking and endocytosis.
Gene Information Card
| Symbol | SYNJ2 |
|---|---|
| Full Name | Synaptojanin 2 |
| Gene Type | protein-coding |
| Chromosomal Location | 6q25.3 |
| NCBI Gene ID | 8871 ncbi.nlm.nih.gov/gene/8871 |
| Ensembl ID | ENSG00000178209 |
| UniProt ID | O15056 |
| OMIM ID | 609410 |
| HGNC ID | 11503 |
| Aliases | INPP5G, KIAA0348 |
Description
SYNJ2 encodes synaptojanin 2, a phosphoinositide 5-phosphatase that dephosphorylates phosphatidylinositol (4,5)-bisphosphate (PIP2) and phosphatidylinositol (3,4,5)-trisphosphate (PIP3). It plays a critical role in clathrin-mediated endocytosis, vesicle trafficking, and actin cytoskeleton dynamics. The protein contains an N-terminal Sac1-like domain and a central 5-phosphatase domain, and is widely expressed with highest levels in brain and testis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Amyotrophic lateral sclerosis (ALS) | Altered endocytosis and vesicle recycling may contribute to motor neuron degeneration. | PMID: 25620204 |
| Schizophrenia | SYNJ2 variants may affect synaptic vesicle dynamics and neurotransmission. | PMID: 21926972 |
| Cancer (breast, lung) | Dysregulation of phosphoinositide signaling promotes cell proliferation and migration. | PMID: 23431137 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 15.2 | High |
| Testis | 12.8 | High |
| Lung | 6.4 | Medium |
| Liver | 3.1 | Low |
| Heart | 2.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 18.5 | Neuronal model |
| A549 (lung carcinoma) | 7.2 | Epithelial |
| MCF7 (breast cancer) | 5.9 | Hormone-responsive |
| HEK293 (embryonic kidney) | 4.3 | Common lab line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2146C>T (p.Arg716Trp) | Missense | 0.01% | Reduced phosphatase activity |
| c.2872G>A (p.Gly958Arg) | Missense | 0.005% | Unknown functional impact |
| c.1234_1235insA | Frameshift | <0.001% | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that truncate the protein or disrupt catalytic domains lead to loss of phosphatase activity.
Gain of Function (GOF)
Not well documented; some missense variants may increase activity but evidence is limited.
Dominant Negative (DN)
Missense mutations in the catalytic domain may interfere with wild-type protein function in dimeric complexes.
View complete mutation data：
Gene Ontology (GO)
| • phosphatidylinositol phosphate phosphatase activity | • phosphatidylinositol-3 |
| • 4 | • 5-trisphosphate 5-phosphatase activity |
| • clathrin-coated vesicle | • synaptic vesicle endocytosis |
| • actin cytoskeleton organization | • phosphatidylinositol dephosphorylation |
Pathways
• Phosphatidylinositol phosphate metabolism (R-HSA-1483255)
• Clathrin-mediated endocytosis (R-HSA-8856828)
• Vesicle-mediated transport (R-HSA-5653656)
Protein Summary
Synaptojanin 2 is a 149-kDa multidomain protein that localizes to clathrin-coated pits and vesicles. It contains an N-terminal Sac1-like domain (phosphatase activity against PI(3)P, PI(4)P) and a central 5-phosphatase domain (dephosphorylates PI(4,5)P2 and PI(3,4,5)P3). The C-terminal region mediates interactions with endocytic proteins such as endophilin. It is essential for efficient synaptic vesicle uncoating and recycling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SYNJ2 Knockout HEK293 Cell Line | EDJ-KQ1006 | Human | 8871 | Details Get a Quote |
| SYNJ2 Knockout A-549 Cell Line | EDJ-KQ21409 | Human | 8871 | Details Get a Quote |
| SYNJ2 Knockout HCT 116 Cell Line | EDJ-KQ21411 | Human | 8871 | Details Get a Quote |
| SYNJ2 Knockout HeLa Cell Line | EDJ-KQ21412 | Human | 8871 | Details Get a Quote |
| SYNJ2BP Knockout HEK293 Cell Line | EDJ-KQ51446 | Human | 55333 | Details Get a Quote |
| SYNJ2BP-COX16 Knockout HEK293 Cell Line | EDJ-KQ52499 | Human | 100529257 | Details Get a Quote |
| SYNJ2BP Knockout HeLa Cell Line | EDJ-KQ56579 | Human | 55333 | Details Get a Quote |
| SYNJ2BP-COX16 Knockout HeLa Cell Line | EDJ-KQ60962 | Human | 100529257 | Details Get a Quote |
| SYNJ2BP Knockout A-549 Cell Line | EDJ-KQ65075 | Human | 55333 | Details Get a Quote |
| SYNJ2BP-COX16 Knockout A-549 Cell Line | EDJ-KQ69437 | Human | 100529257 | Details Get a Quote |
| SYNJ2BP Knockout HCT 116 Cell Line | EDJ-KQ73520 | Human | 55333 | Details Get a Quote |
| SYNJ2BP-COX16 Knockout HCT 116 Cell Line | EDJ-KQ77788 | Human | 100529257 | Details Get a Quote |
| SYNJ2 Knockout HAP1 Cell Line | EDC08034 | Human | 8871 | Details Get a Quote |
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