Ubiquitin-conjugating enzyme E2 R2

Ubiquitin-conjugating enzyme E2 R2 (UBE2R2) is a small E2 ubiquitin-conjugating enzyme that catalyzes the transfer of ubiquitin from E1 activating enzymes to target proteins in collaboration with E3 ubiquitin-protein ligase complexes (UniProt: Q712K3). The protein mediates both monoubiquitination and Lys-48-linked polyubiquitination reactions, and may participate in the degradation of katenin. It functions as part of the ubiquitin–proteasome system, a fundamental cellular quality control mechanism.

UBE2R2 is expressed in human tissues and operates within the broader E2 enzyme family that regulates protein stability and cellular signaling through targeted ubiquitination (UniProt: Q712K3). The UniProt record contains no specific disease associations curated from literature; however, the protein is relevant to proteasomal degradation pathways.

In Alzheimer's Disease, UBE2R2 shows increased abundance in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of +0.472 in one subcellular fraction from TMT-labeled proteomics (Chaparral AD proteomics). This upregulation may reflect altered ubiquitin-dependent protein degradation in the AD brain, though further mechanistic investigation is needed to clarify its role in disease pathogenesis.