PLXNB3
Plexin B3
Gene Information Card
| Symbol | PLXNB3 |
|---|---|
| Full Name | plexin B3 |
| Gene Type | protein-coding |
| Chromosomal Location | Xq28 |
| NCBI Gene ID | 5365 ncbi.nlm.nih.gov/gene/5365 |
| Ensembl ID | ENSG00000198753 |
| UniProt ID | Q9ULL4 |
| OMIM ID | 300214 |
| HGNC ID | 9105 |
| Aliases | PLEXB3, PLXN6, SEMAPHORIN RECEPTOR |
Description
PLXNB3 (plexin B3) is a protein-coding gene located on the X chromosome (Xq28). It encodes a transmembrane receptor for class 4 semaphorins, particularly SEMA4A and SEMA4D, and plays critical roles in axon guidance, cell migration, immune regulation, and tumor progression. The protein contains a Sema domain, PSI domains, and a cytoplasmic GTPase-activating protein (GAP) domain that modulates Rho family GTPases. PLXNB3 is implicated in neurodevelopmental disorders and various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| X-linked intellectual disability | Loss-of-function mutations in PLXNB3 disrupt semaphorin signaling, impairing neuronal connectivity and synaptic function. | PMID: 25217958; ClinVar |
| Prostate cancer | PLXNB3 overexpression promotes tumor cell migration and invasion via SEMA4D signaling and RhoA activation. | PMID: 23542347; COSMIC |
| Melanoma | PLXNB3 mediates SEMA4D-induced angiogenesis and metastasis through activation of the PI3K-Akt pathway. | PMID: 21947068; COSMIC |
| Breast cancer | PLXNB3 expression correlates with poor prognosis and promotes epithelial-mesenchymal transition (EMT). | PMID: 27149990; COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Lung | 8.3 | Low |
| Kidney | 6.1 | Low |
| Testis | 15.2 | Medium |
| Placenta | 9.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 10.2 | Embryonic kidney cells |
| SH-SY5Y | 14.5 | Neuroblastoma cell line |
| PC3 | 18.7 | Prostate cancer cell line |
| MCF7 | 7.4 | Breast cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2146C>T (p.Arg716*) | Nonsense | <0.01% | Loss of function; associated with X-linked intellectual disability |
| c.1234G>A (p.Gly412Arg) | Missense | 0.02% | Reduced semaphorin binding; possible gain of function in cancer |
| c.3010_3011insA (p.Thr1004Asnfs*2) | Frameshift | <0.01% | Loss of function; truncation of GAP domain |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations (e.g., p.Arg716*, p.Thr1004Asnfs*2) that truncate the protein or disrupt the GAP domain, leading to impaired semaphorin signaling and neurodevelopmental phenotypes.
Gain of Function (GOF)
Missense mutations (e.g., p.Gly412Arg) that enhance receptor activity or downstream signaling, potentially promoting tumor cell migration and invasion.
Dominant Negative (DN)
No well-characterized dominant-negative mutations reported for PLXNB3.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Semaphorin signaling (Reactome: R-HSA-373755)
• Axon guidance (KEGG: hsa04360)
• Rho GTPase cycle (Reactome: R-HSA-194840)
Protein Summary
Plexin B3 is a 1,904-amino-acid transmembrane protein with a large extracellular region containing a Sema domain and PSI domains, and a cytoplasmic region with a GAP domain. It functions as a receptor for semaphorins 4A and 4D, transducing signals that regulate cytoskeletal dynamics, cell adhesion, and migration. The GAP domain inactivates R-Ras and activates RhoA, modulating integrin-mediated cell attachment and axon growth cone collapse. PLXNB3 is widely expressed in neural tissues and upregulated in several cancers, where it contributes to tumor progression and metastasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PLXNB3 Knockout HEK293 Cell Line | EDJ-KQ5489 | Human | 5365 | Details Get a Quote |
| PLXNB3 Knockout A-549 Cell Line | EDJ-KQ28714 | Human | 5365 | Details Get a Quote |
| PLXNB3 Knockout HCT 116 Cell Line | EDJ-KQ28715 | Human | 5365 | Details Get a Quote |
| PLXNB3 Knockout HeLa Cell Line | EDJ-KQ28716 | Human | 5365 | Details Get a Quote |
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