BORCS8-MEF2B readthrough gene
A readthrough transcript linking BORCS8 and MEF2B, implicated in transcriptional regulation and cancer
Gene Information Card
| Symbol | BORCS8-MEF2B |
|---|---|
| Full Name | BORCS8-MEF2B readthrough |
| Gene Type | Readthrough (fusion transcript) |
| Chromosomal Location | 19p13.11 (based on component genes BORCS8 and MEF2B) |
| NCBI Gene ID | 100528024 ncbi.nlm.nih.gov/gene/100528024 |
| Ensembl ID | ENSG00000259001 |
| UniProt ID | Not available (no protein product annotated) |
| OMIM ID | Not available |
| HGNC ID | HGNC:40016 |
| Aliases | MEF2B-BORCS8, BORCS8-MEF2B readthrough transcript |
Description
BORCS8-MEF2B is a naturally occurring readthrough transcript that spans the adjacent BORCS8 (BLOC-1 related complex subunit 8) and MEF2B (myocyte enhancer factor 2B) genes on chromosome 19p13.11. This readthrough produces a chimeric mRNA that retains the coding sequence of MEF2B and the 5' UTR of BORCS8. The transcript is predicted to encode a protein identical to MEF2B, as the BORCS8 portion is non-coding. This gene is part of the broader category of readthrough transcription, which can generate novel transcripts and potentially contribute to regulatory complexity. The readthrough is particularly noted in the context of cancer, where MEF2B is a known oncogene in lymphomas.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Diffuse large B-cell lymphoma (DLBCL) | MEF2B mutations (including those in the readthrough transcript) activate the transcription factor, leading to increased expression of target genes such as BCL6 and c-MYC, promoting B-cell proliferation and survival. | COSMIC, ClinVar, literature (e.g., Ying et al., 2013) |
| Follicular lymphoma (FL) | Similar to DLBCL, MEF2B mutations in the readthrough transcript contribute to lymphomagenesis by enhancing transcriptional activity. | COSMIC, ClinVar, literature |
| Other B-cell lymphomas | MEF2B alterations, including those in the readthrough, are recurrent in various B-cell malignancies, suggesting a broad oncogenic role. | COSMIC, literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lymph node | Not available (no specific nTPM data for readthrough; MEF2B is expressed) | MEF2B is highly expressed in germinal center B-cells. |
| Spleen | Not available | MEF2B expressed in B-cell zones. |
| Bone marrow | Not available | MEF2B expressed in hematopoietic progenitors. |
| Brain | Not available | MEF2B is expressed in neurons, but readthrough specificity unknown. |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Ramos (Burkitt lymphoma) | Not available | MEF2B expressed; readthrough may be present. |
| OCI-LY1 (DLBCL) | Not available | MEF2B expressed; readthrough may be present. |
| SU-DHL-4 (DLBCL) | Not available | MEF2B expressed; readthrough may be present. |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.104C>T (p.Pro35Leu) in MEF2B | Missense | Recurrent in DLBCL/FL (~10-15%) | Gain-of-function: increases transcriptional activation of BCL6 and c-MYC. |
| c.109G>A (p.Glu37Lys) in MEF2B | Missense | Recurrent in DLBCL | Gain-of-function: enhances MEF2B activity. |
| c.112A>G (p.Lys38Glu) in MEF2B | Missense | Rare | Gain-of-function: similar effect. |
| c.118G>A (p.Asp40Asn) in MEF2B | Missense | Rare | Gain-of-function: increases activity. |
Mutation functional classification
Loss of Function (LOF)
No loss-of-function mutations reported for MEF2B in the context of the readthrough; MEF2B is primarily oncogenic when mutated.
Gain of Function (GOF)
Mutations in MEF2B (and thus the readthrough) are gain-of-function, leading to increased transcriptional activity and oncogenic signaling.
Dominant Negative (DN)
No dominant-negative effects reported; mutations are activating.
View complete mutation data：
Gene Ontology (GO)
Pathways
• MEF2 signaling pathway
• BCL6 transcriptional regulation
• c-MYC transcriptional regulation
• Germinal center B-cell differentiation
Protein Summary
The BORCS8-MEF2B readthrough transcript is predicted to produce a protein identical to MEF2B, as the BORCS8 portion is non-coding. MEF2B is a member of the myocyte enhancer factor 2 (MEF2) family of transcription factors, which play critical roles in muscle development, neuronal survival, and immune cell function. In B-cells, MEF2B is essential for germinal center formation and regulates the expression of key oncogenes such as BCL6 and c-MYC. Mutations in MEF2B, often occurring in the N-terminal DNA-binding domain, lead to enhanced transcriptional activity and are recurrent in B-cell lymphomas. The readthrough transcript may provide an additional layer of regulation, potentially affecting MEF2B expression or stability. However, no distinct protein product has been experimentally characterized for the readthrough, and its functional significance remains to be fully elucidated.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| BORCS8-MEF2B Knockout HEK293 Cell Line | EDJ-KQ1460 | Human | 4207 | Details Get a Quote |
| BORCS8-MEF2B Knockout A-549 Cell Line | EDJ-KQ21022 | Human | 4207 | Details Get a Quote |
| BORCS8-MEF2B Knockout HCT 116 Cell Line | EDJ-KQ21023 | Human | 4207 | Details Get a Quote |
| BORCS8-MEF2B Knockout HeLa Cell Line | EDJ-KQ77869 | Human | 4207 | Details Get a Quote |
