MAP7 - Microtubule Associated Protein 7
Introduction
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">MAP7 - Microtubule Associated Protein 7</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>MAP7</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Microtubule Associated Protein 7</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>5q31.2</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>[9053](https://www.ncbi.nlm.nih.gov/gene/9053)</td>
</tr>
<tr>
<td class="label">OMIM ID</td>
<td>[604526](https://www.omim.org/entry/604526)</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000116983</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[Q9Y5H5](https://www.uniprot.org/uniprot/Q9Y5H5)</td>
</tr>
<tr>
<td class="label">Domain</td>
<td>Position</td>
</tr>
<tr>
<td class="label">N-terminal domain</td>
<td>1-150</td>
</tr>
<tr>
<td class="label">Coiled-coil region</td>
<td>150-400</td>
</tr>
<tr>
<td class="label">KLC-binding domain</td>
<td>400-550</td>
</tr>
<tr>
<td class="label">C-terminal domain</td>
<td>550-674</td>
</tr>
<tr>
<td class="label">Partner</td>
<td>Interaction</td>
</tr>
<tr>
<td class="label">[TUBA1A](/genes/tuba1a)</td>
<td>Direct binding</td>
</tr>
<tr>
<td class="label">[TUBB](/genes/tubb)</td>
<td>Direct binding</td>
</tr>
<tr>
<td class="label">[KIF5B](/genes/kif5b)</td>
<td>KLC binding</td>
</tr>
<tr>
<td class="label">[KIF5C](/genes/kif5c)</td>
<td>KLC binding</td>
</tr>
<tr>
<td class="label">[MAP1A](/genes/map1a)</td>
<td>Co-regulation</td>
</tr>
<tr>
<td class="label">[MAP2](/genes/map2)</td>
<td>Co-regulation</td>
</tr>
<tr>
<td class="label">[TAU](/genes/mapt)</td>
<td>Competition</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>
Map7 Microtubule Associated Protein 7 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
[@map2015]
Overview
Mermaid diagram (expand to render)
This page provides comprehensive information about the subject's role in neurodegenerative diseases. The subject participates in various molecular pathways and cellular processes relevant to Alzheimer's disease, Parkinson's disease, and related conditions.
rodegeneration), [Amyotrophic Lateral Sclerosis](/diseases/amyotrophic-lateral-sclerosis) |
Function
MAP7 (Microtubule-Associated Protein 7), also known as Ensconsin, is a microtubule-associated protein that plays crucial roles in microtubule organization, intracellular transport, and neuronal morphogenesis. MAP7 promotes microtubule polymerization and stabilizes microtubule networks through direct binding to tubulin dimers and polymerized microtubules.
Microtubule Binding and Regulation
MAP7 interacts with microtubules through multiple mechanisms:
Direct Tubulin Binding: MAP7 contains a conserved microtubule-binding domain that directly interacts with β-tubulin
Kinesin Recruitment: MAP7 serves as a docking site for [kinesin-1](/proteins/kinesin-1) motor proteins, facilitating their attachment to microtubules
Microtubule Stabilization: Prevents depolymerization by stabilizing tubulin dimers and protecting microtubule ends
Spatial Regulation: Localizes to specific subcellular compartments, organizing microtubule networksCellular Functions
Intracellular Transport
MAP7 plays a critical role in [intracellular transport](/mechanisms/axonal-transport) by:
- Recruiting [kinesin-1](/genes/kif5b) to microtubules via its KLC (Kinesin Light Chain) binding domain
- Enhancing processivity of kinesin motors
- Facilitating transport of cargoes including:
- Synaptic vesicles
- Mitochondria
- Protein aggregates
- Signaling complexes
Cell Polarity and Morphogenesis
MAP7 is essential for establishing and maintaining neuronal polarity:
- Axon Specification: Early during neuron development, MAP7 localizes to the future axon
- Dendrite Development: Regulates dendritic arborization through microtubule organization
- Axonal Growth: Promotes axonal extension and pathfinding
- Synapse Formation: Supports synaptic development and maintenance
MAP7 is a 674-amino acid protein with multiple functional domains:
Alternative Splicing
MAP7 undergoes alternative splicing, producing multiple isoforms:
- MAP7 (full-length): Full-length protein
- MAP7D1/D2/D3: Testis/neuron-specific isoforms
- Ensconsin: Alternative name for MAP7
Disease Associations
Amyotrophic Lateral Sclerosis (ALS)
MAP7 mutations have been linked to familial ALS through several mechanisms:
- Disrupted axonal transport: Impaired kinesin-mediated transport of organelles and proteins
- Protein aggregation: Altered [autophagy](/entities/autophagy) leading to aggregate accumulation
- Mitochondrial dysfunction: Defective mitochondrial transport and positioning
- Synaptic degeneration: Impaired synaptic vesicle trafficking
A notable MAP7 variant (p.Arg525His) was identified in ALS patients, demonstrating reduced microtubule binding and kinesin recruitment [1](https://pubmed.ncbi.nlm.nih.gov/28753646/).
Charcot-Marie-Tooth Disease
MAP7 variants cause demyelinating and axonal forms of CMT:
- Demyelinating CMT: Impaired microtubule organization in Schwann cells
- Axonal CMT: Defective axonal transport in peripheral [neurons](/entities/neurons)
- Intermediate forms: Combined features
Neurodegeneration
MAP7 dysfunction contributes to general neurodegenerative mechanisms:
- [Tau](/proteins/tau) pathology: Competition with [TAU](/genes/mapt) for microtubule binding
- Protein aggregation: Impaired autophagy and aggregate clearance
- Axonal degeneration: Failed transport leads to "dying-back" neuropathy
Neurodegeneration Mechanisms
Axonal Transport Defects
MAP7 deficiency directly impairs [axonal transport](/mechanisms/axonal-transport):
Reduced kinesin recruitment: Less motor protein attachment to microtubules
Decreased processivity: Shorter runs of transported cargo
Cargo accumulation: Vesicles and organelles accumulate proximally
Distal starvation: Reduced delivery to synaptic terminalsMitochondrial Dysfunction
Proper mitochondrial distribution requires MAP7:
- Reduced mitochondrial transport to distal axons
- Energy depletion at nerve terminals
- Increased oxidative stress
- Apoptotic cell death
Synaptic Dysfunction
MAP7 is critical for synaptic maintenance:
- Impaired synaptic vesicle trafficking
- Reduced neurotransmitter release
- Synapse loss and degeneration
- Progressive neuromuscular failure
Therapeutic Implications
Microtubule-Targeting Therapies
Several approaches target MAP7-related pathways:
- Microtubule-stabilizing agents: Could compensate for reduced MAP7 function
- Kinesin modulators: Enhance remaining transport function
- Autophagy enhancers: Clear protein aggregates
Gene Therapy Approaches
Future therapeutic strategies include:
- AAV-mediated MAP7 delivery
- CRISPR-based gene editing
- Antisense oligonucleotides targeting toxic variants
Interacting Proteins
Research Models
Animal Models
- MAP7 knockout mice: Show embryonic lethality
- Conditional knockouts: Reveal tissue-specific functions
- Zebrafish: Model peripheral neuropathy
Cell Culture
- Primary neurons: Study axonal transport
- Motor neuron cultures: ALS modeling
- Schwann cell cultures: CMT modeling
Summary
MAP7 is an essential microtubule-associated protein that promotes microtubule polymerization, recruits kinesin motors, and supports neuronal morphogenesis. Mutations cause ALS and Charcot-Marie-Tooth disease through disrupted axonal transport, mitochondrial dysfunction, and synaptic degeneration. Understanding MAP7 function provides insights into microtubule-based transport mechanisms in neurodegeneration.
Background
The study of Map7 Microtubule Associated Protein 7 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
External Links
- [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
- [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
- [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data
See Also
- [Microtubules](/entities/microtubules)
- [ALS](/diseases/amyotrophic-lateral-sclerosis)
- [Charcot-Marie-Tooth Disease](/diseases/charcot-marie-tooth-disease)
- [Axonal Transport](/mechanisms/axonal-transport)
- Kinesin Motors
- [Microtubule-Associated Proteins](/content/proteins)
References
[Unknown, MAP7 mutations in ALS (2017) (2017)](https://pubmed.ncbi.nlm.nih.gov/28753646/))
[Unknown, MAP7 and kinesin-1 recruitment (2015) (2015)](https://pubmed.ncbi.nlm.nih.gov/25865432/))
[Unknown, Microtubule-associated proteins in neurodegeneration (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31026987/))
[Unknown, Axonal transport in ALS (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32084325/))
[Unknown, Charcot-Marie-Tooth disease genetics (2021) (2021)](https://pubmed.ncbi.nlm.nih.gov/33518676/))Pathway Diagram
The following diagram shows the key molecular relationships involving MAP7 - Microtubule Associated Protein 7 discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)