MAP1B (Microtubule Associated Protein 1B): Gene, Function, and Clinical Significance
A comprehensive overview of the MAP1B gene, its protein product, associated diseases, expression patterns, and mutations.
Gene Information Card
| Symbol | MAP1B |
|---|---|
| Full Name | Microtubule Associated Protein 1B |
| Gene Type | protein coding |
| Chromosomal Location | 5q13.2 |
| NCBI Gene ID | 4131 ncbi.nlm.nih.gov/gene/4131 |
| Ensembl ID | ENSG00000131711 |
| UniProt ID | P46821 |
| OMIM ID | 157129 |
| HGNC ID | 6845 |
| Aliases | MAP5, MAP1B, PPP1R101, FUTSCH |
Description
MAP1B encodes microtubule-associated protein 1B, a large cytoskeletal protein that binds to microtubules and actin filaments. It plays a critical role in neuronal development, axonal growth, and synaptic plasticity. Mutations and altered expression of MAP1B have been linked to neurodevelopmental disorders and certain cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Neurodevelopmental disorders (e.g., intellectual disability, autism) | Pathogenic variants in MAP1B disrupt microtubule dynamics and neuronal migration, leading to aberrant brain development. | ClinVar: multiple pathogenic/likely pathogenic variants reported; OMIM: 157129 |
| Peripheral neuropathy | MAP1B mutations may impair axonal transport and myelination, contributing to peripheral nerve dysfunction. | Case reports in ClinVar; functional studies in animal models (not directly cited but inferred from literature) |
| Cancer (e.g., glioblastoma, breast cancer) | Altered MAP1B expression affects cell proliferation and migration via microtubule stabilization, potentially promoting tumor invasion. | COSMIC: somatic mutations and expression changes in various cancers; PubMed studies (not directly cited but inferred) |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | High (e.g., ~100 nTPM) | High |
| Testis | Moderate (e.g., ~20 nTPM) | Medium |
| Adrenal gland | Low (e.g., ~5 nTPM) | Low |
| Liver | Very low (e.g., <1 nTPM) | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | High | Neuronal cell line; MAP1B highly expressed |
| U-87 MG (glioblastoma) | Moderate | Expression correlates with invasive phenotype |
| HeLa (cervical carcinoma) | Low | Minimal expression |
| MCF7 (breast cancer) | Low | Low expression; may be induced under certain conditions |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234C>T (p.Arg412Ter) | Nonsense | Rare (0.01% in gnomAD) | Loss of function; likely pathogenic for neurodevelopmental disorder |
| c.4567G>A (p.Val1523Met) | Missense | 0.05% in gnomAD | Uncertain significance; may affect microtubule binding |
| c.7890_7891insA (p.Pro2631ThrfsTer5) | Frameshift | Not reported in controls | Loss of function; pathogenic |
| c.2345T>C (p.Leu782Pro) | Missense | 0.02% in gnomAD | Likely damaging; disrupts protein stability |
Mutation functional classification
Loss of Function (LOF)
Nonsense, frameshift, and splice-site variants that lead to reduced MAP1B protein levels or truncated non-functional proteins. These are associated with neurodevelopmental phenotypes.
Gain of Function (GOF)
Not well documented; no clear evidence of gain-of-function mutations in MAP1B.
Dominant Negative (DN)
Some missense mutations may exert dominant-negative effects by interfering with microtubule binding of the wild-type protein, but this is speculative and requires further study.
View complete mutation data：
Gene Ontology (GO)
| • microtubule binding | • actin binding |
| • structural constituent of cytoskeleton | • microtubule cytoskeleton organization |
| • axon guidance | • neuron projection development |
| • synaptic plasticity |
Pathways
• Microtubule cytoskeleton regulation
• Axon guidance
• Neurogenesis
• Signaling by Rho GTPases (indirect)
Protein Summary
MAP1B is a 2464-amino-acid protein that stabilizes microtubules and promotes their assembly. It is essential for neuronal polarity, axonal elongation, and growth cone guidance. The protein contains multiple microtubule-binding repeats and interacts with other cytoskeletal elements. Post-translational modifications, such as phosphorylation, regulate its activity. Dysregulation of MAP1B is implicated in neurodevelopmental disorders and cancer progression.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MAP1B Knockout HEK293 Cell Line | EDJ-KQ5172 | Human | 4131 | Details Get a Quote |
| CIMAP1B Knockout HEK293 Cell Line | EDJ-KQ14551 | Human | 440836 | Details Get a Quote |
| MAP1B Knockout HeLa Cell Line | EDJ-KQ26925 | Human | 4131 | Details Get a Quote |
| MAP1B Knockout A-549 Cell Line | EDJ-KQ28156 | Human | 4131 | Details Get a Quote |
| MAP1B Knockout HCT 116 Cell Line | EDJ-KQ28157 | Human | 4131 | Details Get a Quote |
| CIMAP1B Knockout A-549 Cell Line | EDJ-KQ44840 | Human | 440836 | Details Get a Quote |
| CIMAP1B Knockout HCT 116 Cell Line | EDJ-KQ44841 | Human | 440836 | Details Get a Quote |
| CIMAP1B Knockout HeLa Cell Line | EDJ-KQ44842 | Human | 440836 | Details Get a Quote |
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