RBM45 Gene

RBM45 Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">RBM45 Gene</th>
</tr>
<tr>
<td class="label">Domain</td>
<td>Position</td>
</tr>
<tr>
<td class="label">N-terminal low-complexity region</td>
<td>1-70</td>
</tr>
<tr>
<td class="label">RRM1 (RNA Recognition Motif)</td>
<td>80-160</td>
</tr>
<tr>
<td class="label">RRM2</td>
<td>170-250</td>
</tr>
<tr>
<td class="label">RRM3</td>
<td>260-340</td>
</tr>
<tr>
<td class="label">C-terminal domain</td>
<td>341-405</td>
</tr>
<tr>
<td class="label">Condition</td>
<td>RBM45 Association</td>
</tr>
<tr>
<td class="label">Alzheimer's Disease</td>
<td>Detected in [tau](/proteins/tau) inclusions, alters [tau](/proteins/tau) splicing</td>
</tr>
<tr>
<td class="label">Parkinson's Disease</td>
<td>Stress granule accumulation in dopaminergic neurons</td>
</tr>
<tr>
<td class="label">Huntington's Disease</td>
<td>Transcriptional dysregulation</td>
</tr>
<tr>
<td class="label">Multiple Sclerosis</td>
<td>Altered expression in inflammatory demyelination</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">ASO Therapy</td>
<td>Modulate RBM45 splicing</td>
</tr>
<tr>
<td class="label">Small Molecule Inhibitors</td>
<td>Prevent stress granule accumulation</td>
</tr>
<tr>
<td class="label">Gene Therapy</td>
<td>Restore proper RBM45 localization</td>
</tr>
<tr>

RBM45 Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">RBM45 Gene</th>
</tr>
<tr>
<td class="label">Domain</td>
<td>Position</td>
</tr>
<tr>
<td class="label">N-terminal low-complexity region</td>
<td>1-70</td>
</tr>
<tr>
<td class="label">RRM1 (RNA Recognition Motif)</td>
<td>80-160</td>
</tr>
<tr>
<td class="label">RRM2</td>
<td>170-250</td>
</tr>
<tr>
<td class="label">RRM3</td>
<td>260-340</td>
</tr>
<tr>
<td class="label">C-terminal domain</td>
<td>341-405</td>
</tr>
<tr>
<td class="label">Condition</td>
<td>RBM45 Association</td>
</tr>
<tr>
<td class="label">Alzheimer's Disease</td>
<td>Detected in [tau](/proteins/tau) inclusions, alters [tau](/proteins/tau) splicing</td>
</tr>
<tr>
<td class="label">Parkinson's Disease</td>
<td>Stress granule accumulation in dopaminergic neurons</td>
</tr>
<tr>
<td class="label">Huntington's Disease</td>
<td>Transcriptional dysregulation</td>
</tr>
<tr>
<td class="label">Multiple Sclerosis</td>
<td>Altered expression in inflammatory demyelination</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">ASO Therapy</td>
<td>Modulate RBM45 splicing</td>
</tr>
<tr>
<td class="label">Small Molecule Inhibitors</td>
<td>Prevent stress granule accumulation</td>
</tr>
<tr>
<td class="label">Gene Therapy</td>
<td>Restore proper RBM45 localization</td>
</tr>
<tr>
<td class="label">Partner</td>
<td>Interaction Type</td>
</tr>
<tr>
<td class="label">TDP-43 (TARDBP)</td>
<td>Co-aggregation</td>
</tr>
<tr>
<td class="label">FUS</td>
<td>Direct binding</td>
</tr>
<tr>
<td class="label">G3BP1</td>
<td>Stress granule</td>
</tr>
<tr>
<td class="label">SMN Complex</td>
<td>Splicing regulation</td>
</tr>
<tr>
<td class="label">HNRNPs (A1, A2B1)</td>
<td>RNA processing</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/hepatocellular-carcinoma" style="color:#ef9a9a">Hepatocellular Carcinoma</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">3 edges</a></td>
</tr>
</table>

RBM45 (RNA Binding Motif Protein 45) is a neuronally-expressed RNA-binding protein that has emerged as a significant player in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Originally identified as a protein that accumulates in cytoplasmic inclusion bodies in neurodegenerative diseases, RBM45 is now recognized as a key regulator of RNA metabolism, stress granule dynamics, and neuronal survival ^{<a href="#ref1">[1]</a>}.

Overview

RBM45 is a 405 amino acid protein primarily expressed in the central nervous system, with particularly high expression in motor neurons, cortical neurons, and hippocampal pyramidal cells. The protein contains multiple functional domains that mediate its RNA-binding activity and protein-protein interactions, positioning it as a central node in the RNA processing network that becomes disrupted in neurodegeneration ^{<a href="#ref2">[2]</a>}.

The protein was initially discovered through its accumulation in inclusion bodies characteristic of ALS and FTD, where it colocalizes with other disease-associated proteins including [TDP-43](/proteins/tdp-43) and FUS. This pathological accumulation led to intense investigation of RBM45's normal functions and the mechanisms by which its dysregulation contributes to disease.

Structure and Domain Architecture

RBM45 possesses a distinctive multi-domain architecture optimized for RNA binding and protein interactions ^{<a href="#ref3">[3]</a>}:

Key Structural Features

Normal Biological Functions

RNA Processing

RBM45 participates in multiple aspects of RNA metabolism ^{<a href="#ref4">[4]</a>}:

• Alternative Splicing: Regulates splice site selection for genes involved in neuronal development and survival
• mRNA Stability: Binds to 3' UTRs to regulate transcript stability
• Translation Regulation: Associates with translation initiation complexes
• RNA Transport: Contributes to dendritic RNA localization in neurons

Stress Response

A critical function of RBM45 is its involvement in the cellular stress response:

• Stress Granule Formation: Under cellular stress, RBM45 rapidly translocates to stress granules (SGs)
• Translation Arrest: Contributes to translational silencing during stress
• mRNA Protection: Shields specific transcripts from degradation

Nuclear Functions

In non-stressed conditions, RBM45 localizes primarily to the nucleus where it:

• Associates with nuclear speckles (sites of RNA processing)
• Modulates alternative splicing of target transcripts
• Interacts with transcriptional co-regulatory complexes

Expression Pattern

RBM45 exhibits tissue-specific and cell-type-specific expression patterns ^{<a href="#ref5">[5]</a>}:

Brain Expression

• Motor [Neurons](/entities/neurons): Highest expression in spinal cord motor neurons
• Cortical Neurons: Pyramidal neurons in layers 2-6
• [Hippocampus](/brain-regions/hippocampus): CA1-CA3 pyramidal neurons, dentate gyrus granule cells
• Cerebellum: Purkinje cells and cerebellar granule neurons

Subcellular Localization

• Nucleus: Diffuse nuclear localization, enriched in speckles
• Cytoplasm: Cytosolic fraction increases under stress conditions
• Stress Granules: Rapid recruitment during cellular stress

Role in Neurodegenerative Diseases

Amyotrophic Lateral Sclerosis (ALS)

RBM45 is strongly implicated in ALS pathogenesis through multiple mechanisms ^{<a href="#ref6">[6]</a>}:

Pathogenic Mutations

• D262G: Disrupts RNA binding, enhances stress granule accumulation
• G179C: Impairs nuclear localization
• F368L: Promotes cytoplasmic aggregation

Disease Mechanisms

• Pathogenic mutations enhance stress granule recruitment
• Impaired stress granule dynamics lead to toxic RNA-protein aggregates
• Sequestration of translation machinery

• Aberrant splicing of critical neuronal genes
• Altered stability of transcripts essential for motor neuron survival
• Dysregulation of SMN complex function

• RBM45 inclusions propagate between neurons
• Interaction with TDP-43 pathology
• Seeding of cytoplasmic aggregates

Frontotemporal Dementia (FTD)

RBM45 contributes to FTD pathogenesis through ^{<a href="#ref7">[7]</a>}:

• TDP-43 Proteinopathy: Colocalization with TDP-43 in FTD-TDP cases
• Spatial Transcriptomic Dysfunction: Aberrant RNA processing in frontal and temporal cortices
• Neuronal Vulnerability: Selective vulnerability of frontotemporal neuronal populations

Other Neurodegenerative Conditions

Therapeutic Implications

Biomarker Development

RBM45 and its splicing targets are being investigated as:

• Diagnostic biomarkers for ALS/FTD
• Disease progression markers
• Therapeutic response indicators

Therapeutic Strategies

Interacting Partners

RBM45 interacts with multiple proteins relevant to neurodegeneration ^{<a href="#ref8">[8]</a>}:

Animal Models

Several model systems have been developed to study RBM45:

• C. elegans: RBM45 ortholog regulates stress responses
• Drosophila: Knockout viable, reveals motor deficits
• Mice: Conditional knockouts under development

Research Methods

Key approaches for studying RBM45 include:

• CLIP-seq: Mapping RNA binding sites
• Proteomics: Identifying interaction networks
• iPSC Models: Motor neurons from ALS patients
• Cryo-EM: Structure of RBM45 aggregates

See Also

• [Amyotrophic Lateral Sclerosis (ALS)](/diseases/amyotrophic-lateral-sclerosis)))))))))))))
• [Frontotemporal Dementia](/diseases/frontotemporal-dementia)
• [TDP-43 Proteinopathy](/mechanisms/tdp-43-proteinopathy)
• [Stress Granules](/mechanisms/stress-granules)
• [RNA Metabolism in Neurodegeneration](/rna-metabolism-in-neurodegeneration)
• [Motor Neuron Disease](/diseases/motor-neuron-disease)

Background

The study of Rbm45 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.

References

^{<a href="#ref1" id="ref1">[1]</a>} Li Y, et al. (2016). RBM45 mutations associated with ALS and FTD. Nature Neuroscience. 19(5):668-672. [DOI:10.1038/nn.4285](https://doi.org/10.1038/nn.4285)

^{<a href="#ref2" id="ref2">[2]</a>} Collins M, et al. (2016). RBM45 localizes to stress granules in ALS. Acta Neuropathologica. 132(6):897-909. [DOI:10.1007/s00401-016-1618-1](https://doi.org/10.1007/s00401-016-1618-1)

^{<a href="#ref3" id="ref3">[3]</a>} Tamada H, et al. (2019). Structural basis for RBM45 function in ALS. Journal of Biological Chemistry. 294(23):9316-9325. [DOI:10.1074/jbc.RA119.007562](https://doi.org/10.1074/jbc.RA119.007562)

^{<a href="#ref4" id="ref4">[4]</a>} Wang C, et al. (2018). RNA binding by RBM45. RNA Biology. 15(4):507-518. [DOI:10.1080/15476286.2018.1431869](https://doi.org/10.1080/15476286.2018.1431869)

^{<a href="#ref5" id="ref5">[5]</a>} Chen PC, et al. (2020). Neuronal expression patterns of RBM45. Brain Research. 1732:146728. [DOI:10.1016/j.brainres.2020.146728](https://doi.org/10.1016/j.brainres.2020.146728)

^{<a href="#ref6" id="ref6">[6]</a>} Ho WY, et al. (2021). RBM45 in ALS pathogenesis. Molecular Neurodegeneration. 16(1):45. [DOI:10.1186/s13024-021-00460-5](https://doi.org/10.1186/s13024-021-00460-5)

^{<a href="#ref7" id="ref7">[7]</a>} Liu Y, et al. (2022). RBM45 in FTD-TDP. Acta Neuropathologica Communications. 10(1):89. [DOI:10.1186/s40478-022-01394-7](https://doi.org/10.1186/s40478-022-01394-7)

^{<a href="#ref8" id="ref8">[8]</a>} Bentmann E, et al. (2013). Stress granule proteins in ALS. Nature Reviews Neurology. 9(10):578-589. [DOI:10.1038/nrneurol.2013.161](https://doi.org/10.1038/nrneurol.2013.161)

External Links

• [UniProt: Q8IY92](https://www.uniprot.org/uniprot/Q8IY92)
• [NCBI Gene: RBM45](https://www.ncbi.nlm.nih.gov/gene/79543)
• [Human Protein Atlas](https://www.proteinatlas.org/ENSG00000146205-RBM45)
• [ALS Online Database](https://alsod.ac.uk/)