E3 ubiquitin ligase, UBR4 (IPR025704)

Short name: E3_Ub_ligase_UBR4

Overlapping homologous superfamilies


Family relationships



This is a family of E3 ubiquitin ligase enzymes. Members of this family also include auxin transport protein BIG and protein purity of essence. In humans and mouse, E3 ubiquitin-protein ligase is a component of the N-end rule pathway. It recognises and binds to proteins bearing specific N-terminal residues that are destabilising according to the N-end rule, leading to their ubiquitination and subsequent degradation. Together with clathrin, it forms meshwork structures involved in membrane morphogenesis and cytoskeletal organisation. It also regulates integrin-mediated signaling and may play a role in activation of FAK in response to cell-matrix interactions [PMID: 16214886, PMID: 16055722].

Auxin transport protein, as suggested by its name, is required for auxin efflux and polar auxin transport (PAT) influencing auxin-mediated developmental responses (e.g. cell elongation, apical dominance, lateral root production, inflorescence architecture, general growth and development) [PMID: 11485992]. Auxin transport protein is also involved in the elongation of the pedicels and stem internodes through auxin action, the expression/modulation of light-regulated genes, repression of CAB1 and CAB3 genes in etiolated seedlings, etc [PMID: 8314087, PMID: 9165751, PMID: 9390435, PMID: 12834402, PMID: 15634200, PMID: 15681664, PMID: 17652113, PMID: 19176721].

Protein purity of essence, found in Drosophila melanogaster, has a role in growth of the perineurial glial layer of the larval peripheral nerve and it may have a role in male fertility and eye development or function [PMID: 11517334, PMID: 9813038, PMID: 8244010].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.