Ubiquilin-1 (UBQLN1)

Ubiquilin-1 (UBQLN1) is a cytosolic adaptor and shuttle protein that plays a pivotal role in protein quality control by linking the ubiquitination machinery to the proteasome for targeted degradation of misfolded or accumulated proteins[1][2][4][5][6]. It contains an N-terminal ubiquitin-like (UBL) domain and a C-terminal ubiquitin-associated (UBA) domain, allowing it to bind both polyubiquitinated substrates and proteasomal subunits. UBQLN1 also participates in endoplasmic reticulum-associated degradation (ERAD), autophagy (especially autophagosome maturation and fusion), and regulates the cellular abundance of diverse proteins, including the amyloid precursor protein (APP), which is relevant for Alzheimer’s disease. Pathologically, dysregulation or loss of UBQLN1 is implicated in neurodegenerative disease (notably Alzheimer’s and Parkinson’s disease) and cancers, making it a potential therapeutic target for interventions aimed at restoring protein homeostasis or modulating specific disease-related protein degradation pathways[2][3][4][6]. No direct therapeutics currently target UBQLN1 in the clinic, but preclinical data suggest that altering its function may impact disease pathogenesis in neurodegeneration and cancer.

Other names

Ubiquilin-1UBQLN1DA41PLIC1PLIC-1hPLIC-1DSK2XDRP1protein linking IAP with cytoskeleton 1DSK2 homolog (yeast)UBQNtesticular tissue protein Li 219

Indirect: drugs inhibiting γ-secretase increase UBQLN1 protein levels, possibly affecting Aβ processing and AD pathology[4] Potential: targeting UBQLN1’s modulation of proteasomal degradation, autophagy, or APP processing in neurodegeneration or cancer contexts[4][2]