Lipid droplet-regulating VLDL assembly factor AUP1 (AUP1)

Lipid droplet-regulating VLDL assembly factor AUP1 (AUP1) is a multifunctional protein that integrates the endoplasmic reticulum–associated degradation (ERAD) pathway with lipid droplet metabolism[1][5][4]. Localized to both the endoplasmic reticulum (ER) and lipid droplets, AUP1 acts as a molecular scaffold, linking the ubiquitin–proteasome system to intracellular lipid regulation[1]. It is a component of the HRD1–SEL1L degradation complex and is essential for the dislocation and ubiquitination of misfolded proteins in the ER, recruiting E2 ubiquitin-conjugating enzymes via its G2BR domain and modulating polyubiquitination through its CUE domain[1][5]. AUP1 also impacts lipid droplet formation, and its expression levels modulate the abundance of these droplets in cells, providing a mechanistic link between protein quality control and lipid metabolism[2][5][4]. Disease associations include some cancers and viral infections[4]. There are currently no drugs or therapeutic mechanisms directly targeting AUP1, and it is not considered a canonical therapeutic target such as a receptor, enzyme, or transporter.

Other names

Ancient ubiquitous protein 1lipid droplet-regulating VLDL assembly factor AUP1AUP1