TMPO Gene: Thymopoietin, Lamina-Associated Polypeptide 2 (LAP2) Isoforms
Nuclear envelope protein involved in chromatin organization, cell cycle regulation, and linked to cardiomyopathy and cancer.
Gene Information Card
| Symbol | TMPO |
|---|---|
| Full Name | Thymopoietin |
| Gene Type | Protein coding |
| Chromosomal Location | 12q22 |
| NCBI Gene ID | 7112 ncbi.nlm.nih.gov/gene/7112 |
| Ensembl ID | ENSG00000120802 |
| UniProt ID | P42166 |
| OMIM ID | 188380 |
| HGNC ID | 11875 |
| Aliases | LAP2, CMD1T, TP, PRO0868 |
Description
The TMPO gene encodes lamina-associated polypeptide 2 (LAP2), a nuclear envelope protein that binds lamin B and chromatin. Alternative splicing produces multiple isoforms (α, β, γ) with roles in nuclear architecture, cell cycle regulation, and gene expression. Mutations in TMPO are associated with dilated cardiomyopathy and have been implicated in cancer progression.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Dilated cardiomyopathy 1T (CMD1T) | Missense mutations (e.g., p.Arg690Cys) disrupt LAP2 binding to lamin B, impairing nuclear stability. | OMIM #188380; ClinVar |
| Breast cancer | Overexpression of LAP2α correlates with poor prognosis; altered splicing promotes proliferation. | COSMIC; PubMed studies |
| Colorectal cancer | TMPO upregulation linked to tumor progression and metastasis. | COSMIC; PubMed studies |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 12.5 | Medium |
| Skeletal muscle | 8.3 | Low |
| Lung | 6.1 | Low |
| Liver | 4.2 | Low |
| Kidney | 7.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.2 | Cervical cancer cell line |
| K562 | 9.8 | Leukemia cell line |
| MCF7 | 11.4 | Breast cancer cell line |
| HepG2 | 6.5 | Liver cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2068C>T (p.Arg690Cys) | Missense | Rare | Disrupts lamin B binding; associated with dilated cardiomyopathy |
| c.1A>G (p.Met1?) | Start loss | Very rare | Loss of protein expression; likely pathogenic |
| c.1234_1235insA | Frameshift | Rare | Premature truncation; loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift and start-loss mutations lead to truncated or absent LAP2, impairing nuclear envelope integrity.
Gain of Function (GOF)
Not well documented; overexpression in cancer may act as a gain-of-function by promoting proliferation.
Dominant Negative (DN)
Missense mutations (e.g., p.Arg690Cys) may exert dominant-negative effects by competing with wild-type LAP2 for lamin binding.
View complete mutation data：
Gene Ontology (GO)
| • nuclear envelope (GO:0005635) | • nuclear inner membrane (GO:0005637) |
| • chromatin binding (GO:0003682) | • protein binding (GO:0005515) |
| • cell division (GO:0051301) |
Pathways
• Nuclear envelope breakdown and reassembly
• Laminin interactions
• Cell cycle
• mitotic
Protein Summary
Lamina-associated polypeptide 2 (LAP2) is a family of nuclear envelope proteins encoded by TMPO. LAP2α localizes to the nucleoplasm, while LAP2β and γ are integral inner nuclear membrane proteins. They interact with lamin B and chromatin, regulating nuclear structure, DNA replication, and cell cycle progression. Dysregulation contributes to cardiomyopathy and cancer.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TMPO Knockout HEK293 Cell Line | EDJ-KQ3893 | Human | 7112 | Details Get a Quote |
| TMPO Knockout A-549 Cell Line | EDJ-KQ26108 | Human | 7112 | Details Get a Quote |
| TMPO Knockout HCT 116 Cell Line | EDJ-KQ26109 | Human | 7112 | Details Get a Quote |
| TMPO Knockout HeLa Cell Line | EDJ-KQ24760 | Human | 7112 | Details Get a Quote |
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