.infobox .infobox-gene
| Gene Symbol | UBE2B |
|---|---|
| Gene Name | Ubiquitin Conjugating Enzyme E2 B |
| Chromosome | 5q31.1 |
| NCBI Gene ID | 7329 |
| OMIM ID | 604385 |
| Ensembl ID | ENSG00000119009 |
| UniProt ID | P62256 |
| Associated Diseases | Male Infertility, DNA Repair Disorders, Neurodegeneration |
| --- | --- |
| Categories | DNA Repair, Genome Stability, Ubiquitin-Proteasome System |
UBE2B (Ubiquitin-Conjugating Enzyme E2 B) is a member of the E2 ubiquitin-conjugating enzyme family that plays crucial roles in protein ubiquitination, DNA repair, and cellular stress responses. It is particularly important for maintaining genomic integrity in neurons and has been implicated in various neurodegenerative diseases.
UBE2B is an E2 conjugating enzyme that works in conjunction with E3 ubiquitin ligases to transfer ubiquitin to target proteins. Originally identified for its essential role in spermatogenesis, UBE2B has emerged as an important player in neuronal DNA repair and protein quality control mechanisms relevant to neurodegeneration.
UBE2B functions in the ubiquitin-proteasome system (UPS), which is essential for degrading misfolded, oxidized, or otherwise damaged proteins. In neurons, proper UPS function is critical due to the post-mitotic nature of these cells, which cannot rely on cell division to eliminate damaged proteins.
UBE2B participates in several key ubiquitination pathways:
RAD6-RAD18 Mediated Translesion Synthesis: UBE2B works with the E3 ligase RAD18 to monoubiquitinate PCNA (Proliferating Cell Nuclear Anki), which is essential for translesion DNA synthesis past DNA damage [1].
Histone H2B Ubiquitination: UBE2B catalyzes H2B ubiquitination at lysine 120, which regulates transcription elongation and DNA damage response [2].
X-linked Chromatin Regulation: Through its role in histone modification, UBE2B influences gene expression patterns important for neuronal survival.
UBE2B is essential for efficient DNA repair in neurons:
UBE2B is highly expressed in testis and is essential for male fertility. Knockout mice lacking UBE2B exhibit male infertility due to defects in spermatogenesis, highlighting its fundamental role in cell proliferation and differentiation [4].
UBE2B is a 17 kDa protein with a conserved UBC domain characteristic of E2 enzymes. The active site contains a cysteine residue (Cys88) that forms a thioester bond with ubiquitin during the catalytic cycle. The enzyme has a flexible N-terminal region and a core catalytic domain that interacts with various E3 ligases.
UBE2B has been implicated in Alzheimer's disease pathogenesis through several mechanisms:
UBE2B represents a potential therapeutic target for neurodegenerative diseases:
The study of Ube2B 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.