E3 ubiquitin-protein transferase MAEA

MAEA (E3 ubiquitin-protein transferase MAEA) is a core component of the CTLH E3 ubiquitin-protein ligase complex that mediates ubiquitination and proteasomal degradation of specific substrates, including the transcription factor HBP1 (UniProt: Q7L5Y9). The protein is essential for normal cell proliferation and plays a specialized role in erythrocyte maturation and macrophage development, where it facilitates erythroblast enucleation and erythroblastic island formation through interactions with actin and cell-adhesion mechanisms.

MAEA is expressed in tissues involved in hematopoiesis and immune function. UniProt records no primary disease associations for this protein.

In Alzheimer's disease, MAEA protein levels are reduced in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein is significantly downregulated with a mean log2 fold-change of −0.33, suggesting diminished abundance in the disease state. This finding was observed across a single subcellular fraction in a TMT-labeled proteomics analysis of four brain fractions, indicating potential dysregulation of the ubiquitin-proteasome system in AD pathology.