Ancient Ubiquitous Protein 1 (AUP1)

Ancient ubiquitous protein 1 is a protein that contains a domain with homology to the ancient conserved region of the archain 1 gene and a domain that may be involved in binding ubiquitin-conjugating enzymes.

The protein encoded by this gene has been shown to bind to the conserved membrane-proximal sequence of the cytoplasmic tail of integrin alpha(IIb) subunits. These subunits play a crucial role in the integrin alpha(IIb)beta(3) inside-out signalling in platelets and megakaryocytes that leads to platelet aggregation and thrombus formation. This gene overlaps the gene for mitochondrial serine protease 25. AUP1 in lipid droplets, and perhaps at the ER, has a role in ubiquitin-mediated protein degradation by recruiting UBE2G2.