PLXNB1
Plexin B1: A Semaphorin Receptor in Axon Guidance and Cancer
Gene Information Card
| Symbol | PLXNB1 |
|---|---|
| Full Name | plexin B1 |
| Gene Type | protein-coding |
| Chromosomal Location | 3p21.31 |
| NCBI Gene ID | 5364 ncbi.nlm.nih.gov/gene/5364 |
| Ensembl ID | ENSG00000164050 |
| UniProt ID | O43157 |
| OMIM ID | 601053 |
| HGNC ID | 9104 |
| Aliases | PLXN5, SEP, Plexin-5, Semaphorin receptor |
Description
PLXNB1 encodes plexin B1, a transmembrane receptor for class 4 semaphorins (e.g., SEMA4D). It plays a critical role in axon guidance, cell migration, immune regulation, and tumor progression. Binding of semaphorin 4D activates plexin B1, leading to downstream signaling through Rho GTPases, affecting cytoskeletal dynamics and cell adhesion. PLXNB1 is implicated in neurodevelopment, cancer metastasis, and immune cell function.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (multiple types) | PLXNB1 overexpression or mutation promotes tumor cell invasion and metastasis via RhoA/ROCK signaling | COSMIC, ClinVar |
| Neurodevelopmental disorders | Disrupted semaphorin-plexin signaling impairs axon guidance and neuronal migration | OMIM #601053 |
| Immune dysregulation | SEMA4D-PLXNB1 interaction modulates T-cell and dendritic cell function | UniProt O43157 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 15.2 | Medium |
| Lung | 8.7 | Low |
| Kidney | 6.3 | Low |
| Testis | 4.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 12.5 | Embryonic kidney cells |
| SH-SY5Y | 18.3 | Neuroblastoma cells |
| A549 | 9.8 | Lung carcinoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234C>T (p.Arg412Cys) | Missense | <0.1% | Altered ligand binding; potential gain-of-function in cancer |
| c.2567A>G (p.Asn856Ser) | Missense | <0.1% | Unknown significance; reported in COSMIC |
| c.3456_3457insA | Frameshift | <0.1% | Loss-of-function; associated with reduced cell migration |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that truncate the protein impair semaphorin signaling and cell migration.
Gain of Function (GOF)
Missense mutations in the sema domain (e.g., p.Arg412Cys) may enhance receptor activation and promote invasive behavior.
Dominant Negative (DN)
Truncated isoforms lacking the cytoplasmic domain can interfere with wild-type plexin B1 signaling.
View complete mutation data：
Gene Ontology (GO)
| • semaphorin receptor activity | • axon guidance |
| • cell migration | • Rho GTPase binding |
| • signal transduction | • plasma membrane |
Pathways
• Semaphorin interactions
• Axon guidance
• Rho GTPase cycle
• Signaling by Rho family GTPases
Protein Summary
Plexin B1 is a 2135-amino-acid transmembrane protein with an extracellular sema domain, PSI domains, and a cytoplasmic GTPase-activating protein (GAP) domain. It functions as a receptor for SEMA4D, mediating repulsive axon guidance and cell migration. The protein is expressed in neural tissues, lung, kidney, and various cancers. Mutations and altered expression are linked to tumor progression and metastasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PLXNB1 Knockout HEK293 Cell Line | EDJ-KQ1466 | Human | 5364 | Details Get a Quote |
| PLXNB1 Knockout A-549 Cell Line | EDJ-KQ22344 | Human | 5364 | Details Get a Quote |
| PLXNB1 Knockout HCT 116 Cell Line | EDJ-KQ22345 | Human | 5364 | Details Get a Quote |
| PLXNB1 Knockout HeLa Cell Line | EDJ-KQ22346 | Human | 5364 | Details Get a Quote |
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