Disease relevance of UBP1

• Using the method of sib selection, and taking advantage of the fact that bacteria such as Escherichia coli lack ubiquitin-specific enzymes, we have cloned a gene, named UBP1, of the yeast Saccharomyces cerevisiae that encodes a ubiquitin-specific processing protease [1].

High impact information on UBP1

• A deubiquitinating enzyme interacts with SIR4 and regulates silencing in S. cerevisiae [2].
• Ubp2, a deubiquitinating enzyme, was a prominent copurifying protein [3].
• The Deubiquitinating Enzyme Ubp2 Modulates Rsp5-dependent Lys63-linked Polyubiquitin Conjugates in Saccharomyces cerevisiae [4].
• Overexpression of the soluble Ubp1 variant stabilizes the ATP-binding cassette-transporter Ste6, which is transported to the lysosome-like vacuole for degradation, and whose transport is regulated by ubiquitination [5].
• This suggests that the Ubp1 target is a component of the protein transport machinery [5].

Biological context of UBP1

• Ubp2 (1,264 residues), Ubp3 (912 residues), and the previously cloned Ubp1 (809 residues) are largely dissimilar except for two short regions containing Cys and His which encompass their putative active sites [6].
• The amino acid sequence of the 809-residue UBP1 lacks significant similarities to other known proteins, including the 236-residue YUH1 protease [1].
• On Ubp1 overexpression, Ste6 accumulates at the cell surface, which is consistent with a role of Ubp1 at the internalization step of endocytosis or with enhanced recycling to the cell surface from an internal compartment [5].
• Additional PIPs include the heat shock proteins Hsp70 and Hsp82, the deubiquitinating enzyme Ubp6, and proteins involved in transcriptional control, mitosis, tubulin assembly, RNA metabolism, and signal transduction [7].
• UBP10 codes for a deubiquitinating enzyme of Saccharomyces cerevisiae whose loss of function determines slow growth rate and partial impairment of silencing at telomeres and HM loci [8].

Anatomical context of UBP1

• In contrast to UBP1, another oligouridylate-binding nuclear three-RBD protein of N. plumbaginifolia (Lambermon et al., EMBO J, 2000, 19:1638-1649), RBP45 and RBP47 do not stimulate mRNA splicing and accumulation when transiently overexpressed in protoplasts [9].
• The yeast deubiquitinating enzyme Ubp16 is anchored to the outer mitochondrial membrane [10].
• The Drosophila fat facets gene encodes a deubiquitinating enzyme required during eye development to limit the number of photoreceptors in each facet to eight [11].
• We looked for membrane-associated Dubs (deubiquitinating enzymes) among the 16 yeast members of the ubiquitin-specific processing protease (Ubp) family to identify potential regulators of ubiquitin-dependent processes at membranes [10].

Associations of UBP1 with chemical compounds

• The Histone Deubiquitinating Enzyme Ubp10 Is Involved in rDNA Locus Control in Saccharomyces cerevisiae by Affecting Sir2p Association [12].

Physical interactions of UBP1

• Here, we show that the deubiquitinating enzyme Ubp3p interacts with Atg19p [13].

Enzymatic interactions of UBP1

• With the exception of polyubiquitin, the UBP1 protease cleaves at the carboxyl terminus of the ubiquitin moiety in natural and engineered fusions irrespective of their size or the presence of an amino-terminal ubiquitin extension [1].

Other interactions of UBP1

• YUH1 and UBP1, the genes for two ubiquitin-specific proteases of the yeast Saccharomyces cerevisiae, have been cloned previously and shown to encode nonhomologous proteins [6].
• Ste6 stabilization was not the result of a general increase in deubiquitination activity, because overexpression of Ubp1 had no effect on the degradation of the ER-associated degradation substrate carboxypeptidase Y* and most importantly on Ste6 ubiquitination itself [5].
• Another yeast deubiquitinating enzyme, Ubp5, which is related in sequence to Doa4 but cannot substitute for it even when overproduced, does not associate with the proteasome [14].
• The deubiquitinating enzyme Doa4p protects cells from DNA topoisomerase I poisons [15].
• The influence of Ubp14p, a deubiquitinating enzyme, on proteasome-dependent catabolite degradation was further uncovered [16].

References