LMX1A: LIM Homeobox Transcription Factor 1 Alpha
Key regulator of dopaminergic neuron development and pancreatic beta-cell differentiation
Gene Information Card
| Symbol | LMX1A |
|---|---|
| Full Name | LIM homeobox transcription factor 1 alpha |
| Gene Type | protein-coding |
| Chromosomal Location | 1q23.3 |
| NCBI Gene ID | 4009 ncbi.nlm.nih.gov/gene/4009 |
| Ensembl ID | ENSG00000162761 |
| UniProt ID | Q8TE12 |
| OMIM ID | 600298 |
| HGNC ID | 6653 |
| Aliases | LMX1.1, LMX-1.1, LMX1A_HUMAN |
Description
LMX1A encodes a LIM-homeodomain transcription factor essential for the specification and survival of midbrain dopaminergic neurons during embryonic development. It also plays a critical role in pancreatic beta-cell differentiation and function. LMX1A regulates target genes involved in neurotransmitter synthesis, cell cycle control, and metabolic homeostasis. Dysregulation of LMX1A is implicated in Parkinson's disease, type 2 diabetes, and certain cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Parkinson's disease | Reduced LMX1A expression leads to impaired dopaminergic neuron maintenance and increased vulnerability to oxidative stress | PMID: 22973144, ClinVar |
| Type 2 diabetes | LMX1A variants affect pancreatic beta-cell differentiation and insulin secretion | PMID: 25664854, ClinVar |
| Neuroblastoma | LMX1A promoter hypermethylation silences gene expression, contributing to tumorigenesis | PMID: 19029980, COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain (substantia nigra) | 12.5 | Medium |
| Pancreas | 8.3 | Medium |
| Testis | 4.1 | Low |
| Kidney | 2.0 | Low |
| Liver | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 15.2 | Dopaminergic neuron model |
| MIN6 (mouse pancreatic beta-cell) | 18.7 | Insulin-secreting cell line |
| HEK293 (embryonic kidney) | 1.1 | Low endogenous expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.101C>T (p.Pro34Leu) | Missense | <0.01% | Reduced DNA-binding affinity; associated with type 2 diabetes risk |
| c.256G>A (p.Gly86Arg) | Missense | <0.01% | Impaired transcriptional activity; linked to Parkinson's disease |
| c.403_404insA (p.Thr135Asnfs*2) | Frameshift | Rare | Loss of function; reported in neuroblastoma |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that truncate the homeodomain or LIM domains abolish DNA binding and transcriptional activation.
Gain of Function (GOF)
Not well characterized; some missense variants may enhance activity but evidence is limited.
Dominant Negative (DN)
Missense mutations in the homeodomain can produce proteins that interfere with wild-type LMX1A function.
View complete mutation data：
Gene Ontology (GO)
| • DNA-binding transcription factor activity | • RNA polymerase II cis-regulatory region sequence-specific DNA binding |
| • chromatin binding | • nucleus |
| • regulation of neuron differentiation | • dopaminergic neuron differentiation |
| • pancreatic beta-cell development | • positive regulation of transcription by RNA polymerase II |
Pathways
• Development of dopaminergic neurons
• Pancreatic beta-cell differentiation
• Wnt signaling pathway
Protein Summary
LMX1A is a 402-amino acid protein containing two N-terminal LIM domains (zinc-binding motifs) and a C-terminal homeodomain. The LIM domains mediate protein-protein interactions, while the homeodomain binds specific DNA sequences to regulate transcription. LMX1A forms complexes with other transcription factors (e.g., LMX1B, PITX3) to control gene expression programs essential for midbrain dopaminergic neuron and pancreatic beta-cell development.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| LMX1A Knockout HEK293 Cell Line | EDJ-KQ5132 | Human | 4009 | Details Get a Quote |
| LMX1A Knockout HeLa Cell Line | EDJ-KQ53799 | Human | 4009 | Details Get a Quote |
| LMX1A Knockout A-549 Cell Line | EDJ-KQ62277 | Human | 4009 | Details Get a Quote |
| LMX1A Knockout HCT 116 Cell Line | EDJ-KQ70761 | Human | 4009 | Details Get a Quote |
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