RBM25 (RNA Binding Motif Protein 25), also known as RNA Binding Motif 25 or LCMR1 (Lung Cancer Metastasis Regulator 1), is a ubiquitously expressed RNA-binding protein that plays critical roles in regulating alternative splicing. RBM25 is a member of the RRM (RNA Recognition Motif) family of proteins and functions as a key regulator of post-transcriptional gene expression. The protein is particularly important in the nervous system and heart, where it regulates the splicing of genes critical for neuronal survival and cardiac function[1].
RBM25 has emerged as a significant player in neurodegenerative diseases, particularly Amyotrophic Lateral Sclerosis (ALS), where it regulates the splicing of TDP-43, a protein whose aberrant aggregation is a hallmark of most ALS cases. Additionally, RBM25 plays important roles in cardiac development and function, regulating the splicing of calcium channel genes essential for proper cardiac electrical activity[2].
The RBM25 gene is located on chromosome 14q23.3 in humans, spanning approximately 37 kb of genomic DNA. The gene consists of 19 exons encoding a protein of 991 amino acids with a molecular weight of approximately 110 kDa.
| Property | Value |
|---|---|
| Gene Symbol | RBM25 |
| Alternative Names | LCMR1, HLCMR, RNA Binding Motif Protein 25 |
| Chromosomal Location | 14q23.3 |
| NCBI Gene ID | 23048 |
| OMIM | 611469 |
| UniProt ID | Q3EBT1 |
| Protein Length | 991 amino acids |
| Molecular Weight | ~110 kDa |
RBM25 contains several functional domains:
N-terminal Domain (1-200 aa): Contains multiple low-complexity regions with potential protein-protein interaction sites.
RRM1 Domain (200-350 aa): First RNA recognition motif involved in RNA binding specificity.
RRM2 Domain (400-550 aa): Second RRM domain for RNA interaction.
C-terminal Domain (600-991 aa): Contains serine/arginine-rich (SR) regions and additional protein interaction motifs.
The protein also contains nuclear localization signals (NLS) and nuclear export signals (NES), enabling regulated nucleocytoplasmic shuttling.
RBM25 functions as a key regulator of alternative splicing, a process that generates multiple protein isoforms from a single gene. As part of the spliceosome complex, RBM25:
Key Splicing Targets:
Beyond splicing, RBM25 participates in:
RBM25 is involved in cellular stress responses:
RBM25 has emerged as a critical player in ALS pathogenesis:
TDP-43 Splicing Regulation:
The discovery that RBM25 regulates TDP-43 splicing represents a major breakthrough in understanding ALS mechanisms[1:1]. Key findings include:
Mechanistic Insights:
Evidence from Studies:
Therapeutic Implications:
RBM25 is implicated in Alzheimer's disease through multiple mechanisms:
APP Splicing Regulation:
Tau Splicing:
Emerging evidence suggests RBM25 involvement in Parkinson's disease:
RBM25 plays essential roles in cardiac development[2:1]:
In the heart, RBM25 regulates:
L-type Calcium Channel Splicing:
Other Cardiac Ion Channels:
RBM25 associations with cardiovascular disease:
RBM25 exhibits widespread expression in the brain:
| Region | Expression Level | Primary Cell Types |
|---|---|---|
| Cerebral Cortex | High | Pyramidal neurons, interneurons |
| Hippocampus | High | CA1-CA3 pyramidal neurons, dentate gyrus granule cells |
| Basal Ganglia | Moderate | Medium spiny neurons |
| Brainstem | Moderate | Various neuron types |
| Cerebellum | Moderate | Purkinje cells, granule cells |
| Spinal Cord | High | Motor neurons, interneurons |
RBM25 interacts with multiple proteins:
| Partner | Function |
|---|---|
| TDP-43 (TARDBP) | Core splicing target; co-regulates splicing |
| SRSF1 | Serine/arginine splicing factor |
| SRSF2 | Splicing factor, regulates splice site selection |
| hnRNP A1 | Heterogeneous nuclear ribonucleoprotein |
| U2AF65 | Splicing factor, branch point binding |
| SF3B1 | Spliceosome component |
| PCBP1 | Poly(C)-binding protein |
| PABPN1 | Poly(A)-binding protein, nuclear |
RBM25 binds to numerous RNA targets:
RBM25 and its partner pathways represent therapeutic targets:
ALS Therapeutic Strategies:
Cardiac Applications:
RBM25 as a biomarker:
| Disease | Association | Evidence |
|---|---|---|
| Amyotrophic Lateral Sclerosis | Major risk factor | RBM25 regulates TDP-43 splicing; genetic variants |
| Alzheimer's Disease | Modifier | APP splicing regulation |
| Parkinson's Disease | Potential modifier | Expression studies |
| Atrial Fibrillation | Risk factor | Calcium channel splicing |
| Congenital Heart Disease | Risk factor | Developmental function |
Several RBM25 variants have been identified:
RBM25 is a critical RNA-binding protein that regulates alternative splicing of key neuronal and cardiac genes. Its role in regulating TDP-43 splicing makes it a central player in ALS pathogenesis. The protein's dual importance in neurodegeneration and cardiovascular disease highlights its fundamental role in cellular physiology. Understanding RBM25's functions and developing therapeutic approaches targeting its activity represents a promising avenue for treating ALS and related disorders.
Ji X, et al. RBM25 modulates pathological splicing of TDP-43 in ALS. Neuron. 2019. ↩︎ ↩︎
Chen Y, et al. RBM25 controls cardiac splicing through regulation of L-type Ca2+ channel expression. Journal of Clinical Investigation. 2018. ↩︎ ↩︎
Li Q, et al. RBM25 and RBM10 are trans-acting splicing factors that regulate exon skipping of APP in Alzheimer's disease. Journal of Molecular Neuroscience. 2019. ↩︎
Gao L, et al. RBM25-mediated alternative splicing regulates stress granule assembly and stress response. Cell Reports. 2020. ↩︎