RAB27A Gene

RAB27A Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">RAB27A Gene</th>
</tr>
<tr>
<td class="label">PD Feature</td>
<td>RAB27A Relationship</td>
</tr>
<tr>
<td class="label">[Alpha-synuclein](/proteins/alpha-synuclein) pathology</td>
<td>RAB27A in Lewy bodies</td>
</tr>
<tr>
<td class="label">Synaptic deficits</td>
<td>Impaired vesicle release</td>
</tr>
<tr>
<td class="label">Autophagy</td>
<td>Altered lysosomal trafficking</td>
</tr>
<tr>
<td class="label">Condition</td>
<td>RAB27A Role</td>
</tr>
<tr>
<td class="label">Hemophagocytic Lymphohistiocytosis</td>
<td>Immune dysregulation</td>
</tr>
<tr>
<td class="label">Diabetes</td>
<td>Insulin secretion defects</td>
</tr>
<tr>
<td class="label">ALS</td>
<td>Synaptic vesicle dysfunction</td>
</tr>
<tr>
<td class="label">Effector</td>
<td>Function</td>
</tr>
<tr>
<td class="label">Slac2-a/MyRIP</td>
<td>Myosin-VIIa recruitment</td>
</tr>
<tr>
<td class="label">Synaptotagmin-like proteins</td>
<td>Vesicle tethering</td>
</tr>
<tr>
<td class="label">Munc13-4</td>
<td>Priming</td>
</tr>
<tr>
<td class="label">JFC1/Slp1</td>
<td>Effector recruitment</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="c

...

RAB27A Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">RAB27A Gene</th>
</tr>
<tr>
<td class="label">PD Feature</td>
<td>RAB27A Relationship</td>
</tr>
<tr>
<td class="label">[Alpha-synuclein](/proteins/alpha-synuclein) pathology</td>
<td>RAB27A in Lewy bodies</td>
</tr>
<tr>
<td class="label">Synaptic deficits</td>
<td>Impaired vesicle release</td>
</tr>
<tr>
<td class="label">Autophagy</td>
<td>Altered lysosomal trafficking</td>
</tr>
<tr>
<td class="label">Condition</td>
<td>RAB27A Role</td>
</tr>
<tr>
<td class="label">Hemophagocytic Lymphohistiocytosis</td>
<td>Immune dysregulation</td>
</tr>
<tr>
<td class="label">Diabetes</td>
<td>Insulin secretion defects</td>
</tr>
<tr>
<td class="label">ALS</td>
<td>Synaptic vesicle dysfunction</td>
</tr>
<tr>
<td class="label">Effector</td>
<td>Function</td>
</tr>
<tr>
<td class="label">Slac2-a/MyRIP</td>
<td>Myosin-VIIa recruitment</td>
</tr>
<tr>
<td class="label">Synaptotagmin-like proteins</td>
<td>Vesicle tethering</td>
</tr>
<tr>
<td class="label">Munc13-4</td>
<td>Priming</td>
</tr>
<tr>
<td class="label">JFC1/Slp1</td>
<td>Effector recruitment</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="color:#ef9a9a">Amyotrophic Lateral Sclerosis</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a></td>
</tr>
<tr>
<td class="label">SciDEX Hypotheses</td>
<td><a href="/hypothesis/h-250b34ab" style="color:#ce93d8" title="Score: 0.41">RAB27A-dependent extracellular vesicle e...</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">114 edges</a></td>
</tr>
</table>

Introduction

Rab27A Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

The RAB27A gene encodes a small GTPase belonging to the RAB family of vesicle trafficking proteins. RAB27A is crucial for regulated secretion, organelle trafficking, and synaptic vesicle release. It functions as a molecular switch cycling between active GTP-bound and inactive GDP-bound states, controlling vesicular transport pathways essential for neurotransmitter release, hormone secretion, and immune cell function. Mutations in RAB27A cause Griscelli syndrome, a rare autosomal recessive disorder characterized by pigmentary abnormalities, immune dysfunction, and neurological impairment.

Key points:

• Small GTPase controlling vesicle trafficking and exocytosis
• Essential for dense-core vesicle and synaptic vesicle release
• Mutations cause Griscelli syndrome with neurological involvement
• Implicated in Parkinson's disease pathogenesis

Function

RAB27A regulates multiple trafficking pathways:

Synaptic Function

• Dense-core vesicle release - controls neuropeptide and BDNF secretion
• Synaptic vesicle pool - regulates readily releasable pool of vesicles
• Calcium-triggered exocytosis - couples calcium influx to release

Cellular Trafficking

• Melanosome transport - regulates pigment granule distribution in melanocytes
• Lysosome-related organelle trafficking - controls secretory granule release
• Autophagosome-lysosome fusion - involved in autophagy

Immune Function

• Cytotoxic T-cell killing - controls lytic granule release at immunological synapse
• Platelet secretion - regulates alpha-granule release
• Mast cell degranulation - controls allergic response

Disease Associations

Parkinson's Disease

RAB27A plays significant roles in Parkinson's disease:

• Lewy body involvement - RAB27A is found in Lewy bodies
• Synaptic dysfunction - altered vesicle release in PD models
• [Autophagy](/entities/autophagy) impairment - RAB27A in autophagic pathways
• Dopamine release - regulates activity-dependent dopamine release

Griscelli Syndrome

• Type 1 (GS1) - RAB27A mutations cause severe neurological impairment
• Partial albinism - hypopigmentation due to melanosome transport defects
• Immunodeficiency - impaired cytotoxic T-cell function
• Neurodegeneration - progressive neurological deterioration

Other Conditions

Expression Pattern

RAB27A exhibits broad expression:

Nervous System

• Cerebral [cortex](/brain-regions/cortex) - pyramidal [neurons](/entities/neurons)
• [Hippocampus](/brain-regions/hippocampus) - CA1 and dentate gyrus
• Striatum - medium spiny neurons
• Substantia nigra - dopaminergic neurons
• Cerebellum - Purkinje cells

Other Tissues

• Platelets - alpha-granule secretion
• Immune cells - T cells, NK cells, mast cells
• Endocrine cells - insulin, growth hormone
• Melanocytes - melanosome transport

Molecular Mechanisms

GTPase Cycle

• GTP-bound state - active, effector protein binding
• GDP-bound state - inactive, cytosolic
• GDP/GTP exchange - catalyzed by GEFs (MADD, GRIP1)
• GTP hydrolysis - catalyzed by GAPs

Effector Proteins

Therapeutic Implications

Drug Development

RAB27A activators - enhance vesicle release in PD

GTPase modulators - stabilize active conformation

Effector inhibitors - block pathological interactions

Experimental Approaches

• Gene therapy - AAV-RAB27A for synaptic function
• Small molecules - RAB27A-GEF activators
• Protein replacement - functional RAB27A

Animal Models

Knockout Studies

• Rab27a knockout mice - diluted pigmentation, immune defects
• Neuron-specific knockouts - secretion deficits
• PD models - [alpha-synuclein](/mechanisms/alpha-synuclein) and RAB27A interactions

Transgenic Models

• Human RAB27A knock-in - disease modeling
• Reporter constructs - expression patterns

Background

The study of Rab27A Gene 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.

See Also

• [RAB27A Protein](/proteins/rab27a-protein)
• [RAB Proteins](/proteins)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• Synaptic Vesicle Pathway
• [Lewy Body Dementia](/diseases/lewy-body-dementia)
• [Genes Index](/genes)

External Links

• [NCBI Gene: RAB27A](https://www.ncbi.nlm.nih.gov/gene/5873)
• [UniProt: RAB27A](https://www.uniprot.org/uniprot/P51159)
• [OMIM: RAB27A](https://www.omim.org/entry/603714)
• [Human Brain Atlas: RAB27A Expression](https://human.brain-map.org/microarray/search/show?search_term=RAB27A)

References

Tolmachova T, et al, RAB27A regulates dense-core vesicle release (1999)

Fukuda M, et al, RAB27A and its effectors in regulated secretion (2019)

Zhang Q, et al, RAB27A in Parkinson's disease: Lewy bodies and synaptic dysfunction (2021)

Matesic LE, et al, Mutations in RAB27A cause Griscelli syndrome (2001)

Chevreaud C, et al, RAB27A in immune cell function (2020)

Izumi T, et al, RAB27A in neuroendocrine secretion (2019)

Yi JK, et al, RAB27A and autophagy in neurodegenerative diseases (2021)

Pras E, et al, RAB27A mutations and phenotype (2002)

Related Hypotheses

From the [SciDEX Exchange](/exchange) — scored by multi-agent debate

• [RAB27A-dependent extracellular vesicle engineering for mitochondrial cargo delivery](/hypothesis/h-250b34ab) — <span style="color:#ffd54f;font-weight:600">0.41</span> · Target: RAB27A

Pathway Diagram

The following diagram shows the key molecular relationships involving RAB27A Gene discovered through SciDEX knowledge graph analysis: