InterPro domain: IPR039732

This entry includes Hub1 from yeasts and Ubl5 from animals. Hub1 is an ubiquitin-like protein that lacks the C-terminal Gly, which is essential for covalent attachment to target protein(s) of ubiquitin and other ubiquitin-like (UBL) modifiers [ 1 ]. Hub1 binds non-covalently to a conserved element termed HIND, which is present in the spliceosomal protein Snu66 in yeast and mammals, and Prp38 in plants [ 2 , 3 ]. Hub1 does not affect general splicing, instead, it acts as a modulator of spliceosome performance and facilitator of alternative splicing [ 4 ]. It has been shown to bind to the DEAD-box helicase Prp5 and mediates enhanced, but error-prone splicing [ 5 ].

1. Hub1 is an essential ubiquitin-like protein without functioning as a typical modifier in fission yeast. Genes Cells 9, 1189-97
2. Ubiquitin-like protein Hub1 is required for pre-mRNA splicing and localization of an essential splicing factor in fission yeast. Curr. Biol. 14, 2283-8
3. Role of the ubiquitin-like protein Hub1 in splice-site usage and alternative splicing. Nature 474, 173-8
4. The conserved ubiquitin-like protein Hub1 plays a critical role in splicing in human cells. J Mol Cell Biol 6, 312-23
5. Error-Prone Splicing Controlled by the Ubiquitin Relative Hub1. Mol. Cell 67, 423-432.e4