** is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
Structure
UBC9 is the sole E2 conjugating enzyme for SUMO (Small Ubiquitin-like Modifier) conjugation. It has a characteristic UBC9 fold consisting of a four-helix bundle structure that facilitates binding to SUMO and SUMOylated substrates. The active site contains a conserved cysteine residue (Cys93) that forms a thioester bond with SUMO during the conjugation process.
Domain Architecture
UBC9 Fold: Residues 1-158 - Catalytic core with SUMO-binding groove
Active Site: Cys93 - Forms thioester intermediate with SUMO
NLS/NES: Nuclear localization and export signals for shuttling
** is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
Structure
UBC9 is the sole E2 conjugating enzyme for SUMO (Small Ubiquitin-like Modifier) conjugation. It has a characteristic UBC9 fold consisting of a four-helix bundle structure that facilitates binding to SUMO and SUMOylated substrates. The active site contains a conserved cysteine residue (Cys93) that forms a thioester bond with SUMO during the conjugation process.
Domain Architecture
UBC9 Fold: Residues 1-158 - Catalytic core with SUMO-binding groove
Active Site: Cys93 - Forms thioester intermediate with SUMO
NLS/NES: Nuclear localization and export signals for shuttling
Normal Function in the Nervous System
UBC9 plays critical roles in neuronal cells:
SUMOylation: Catalyzes covalent attachment of SUMO to target proteins
Transcriptional Regulation: Modifies transcription factors and co-regulators
DNA Repair: Involved in genome stability through SUMOylation of repair proteins
Synaptic Plasticity: Regulates synaptic protein function through SUMOylation
Stress Response: Mediates cellular stress responses through SUMO-dependent pathways
UBC9 is essential for neuronal survival and function. It regulates numerous substrates involved in synaptic transmission, mitochondrial function, and protein quality control.
Role in Neurodegeneration
Alzheimer's Disease
UBC9 and SUMOylation are implicated in AD pathogenesis: