[5][6][7] The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family.

Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains.

The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility.

UP1a may play a role in normal bladder epithelial physiology, possibly in regulating membrane permeability of superficial umbrella cells or in stabilizing the apical membrane through AUM/cytoskeletal interactions.

This article on a gene on human chromosome 19 is a stub.