Ubiquitin-fold modifier 1 (IPR005375)

Short name: UFM1

Overlapping homologous superfamilies

Family relationships



Ubiquitinylation is an ATP-dependent process that involves the action of at least three enzymes: a ubiquitin-activating enzyme (E1, IPR000011), a ubiquitin-conjugating enzyme (E2, IPR000608), and a ubiquitin ligase (E3, IPR000569, IPR003613), which work sequentially in a cascade. There are many different E3 ligases, which are responsible for the type of ubiquitin chain formed, the specificity of the target protein, and the regulation of the ubiquitinylation process [PMID: 12646216]. Ubiquitinylation is an important regulatory tool that controls the concentration of key signalling proteins, such as those involved in cell cycle control, as well as removing misfolded, damaged or mutant proteins that could be harmful to the cell. Several ubiquitin-like molecules have been discovered, such as Ufm1 (IPR005375), SUMO1 (IPR003653), NEDD8, Rad23 (IPR004806), Elongin B and Parkin (IPR003977), the latter being involved in Parkinson's disease [PMID: 15564047].

Ubiquitin-like molecules (UBLs) can be divided into two subclasses: type-1 UBLs, which ligate to target proteins in a manner similar, but not identical, to the ubiquitylation pathway, such as SUMO, NEDD8, and UCRP/ISG15, and type-2 UBLs (also called UDPs, ubiquitin-domain proteins), which contain ubiquitin-like structure embedded in a variety of different classes of large proteins with apparently distinct functions, such as Rad23, Elongin B, Scythe, Parkin, and HOIL-1.

This entry represents Ufm1 (ubiquitin-fold modifier), which is a ubiquitin-like protein with structural similarities to ubiquitin [PMID: 10884686, PMID: 15071506]. Ufm1 is one of a number of ubiquitin-like modifiers that conjugate to target proteins in cells through Uba5 (E1) and Ufc1 (E2). The Ufm1-system is conserved in metazoa and plants, suggesting it has a potential role in multicellular organisms [PMID: 16527251]. Human Ufm1 is synthesized as a precursor consisting of 85 amino-acid residues. Prior to activation by Uba5, the extra amino acids at the C-terminal region of Ufm1 are removed to expose Gly, which is necessary for conjugation to target molecule(s). C-terminal processing of Ufm1 requires two specific cysteine peptidases (IPR012462): UfSP1 and UfSP2; both peptidases are also able to release Ufm1 from Ufm1-conjugated cellular proteins. UfSP2 is present in most, if not all, of multi-cellular organisms including plant, nematode, fly, and mammal, whereas UfSP1 is not present in plants and nematodes [PMID: 17182609].

Contributing signatures

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