UBA52

Ubiquitin is a highly conserved nuclear and cytoplasmic protein that has a major role in targeting cellular proteins for degradation by the 26S proteosome. It is also involved in the maintenance of chromatin structure, the regulation of gene expression, and the stress response. Ubiquitin is synthesized as a precursor protein consisting of either polyubiquitin chains or a single ubiquitin moiety fused to an unrelated protein. This gene encodes a fusion protein consisting of ubiquitin at the N terminus and ribosomal protein L40 at the C terminus, a C-terminal extension protein (CEP). Multiple processed pseudogenes derived from this gene are present in the genome. [provided by RefSeq, Jul 2008]

Ubiquitin-60S ribosomal protein L40

Ubiquitin
Exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in proteotoxic stress response and cell cycle; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.
60S ribosomal protein L40
Component of the 60S subunit of the ribosome (PubMed:23169626, PubMed:23636399, PubMed:32669547).
Ribosomal protein L40 is essential for translation of a subset of cellular transcripts, and especially for cap-dependent translation of vesicular stomatitis virus mRNAs (PubMed:23169626, PubMed:23636399, PubMed:32669547).

Biological Process cytoplasmic translation Source:ComplexPortal1 Publication
Biological Process modification-dependent protein catabolic process Source:GO_Central1 Publication
Biological Process protein modification process Source:ProtInc1 Publication
Biological Process protein ubiquitination Source:GO_Central1 Publication
Biological Process translation Source:UniProtKB

Ubiquitin
Cytoplasm
Nucleus
60S ribosomal protein L40
Cytoplasm

Ubiquitin
Phosphorylated at Ser-65 by PINK1 during mitophagy (PubMed:24660806, PubMed:24751536, PubMed:24784582, PubMed:25474007, PubMed:25527291).
Phosphorylated ubiquitin specifically binds and activates parkin (PRKN), triggering mitophagy (PubMed:24660806, PubMed:24751536, PubMed:24784582, PubMed:25474007, PubMed:25527291).
Phosphorylation does not affect E1-mediated E2 charging of ubiquitin but affects discharging of E2 enzymes to form polyubiquitin chains. It also affects deubiquitination by deubiquitinase enzymes such as USP30 (PubMed:25527291).
Ubiquitin
Mono-ADP-ribosylated at the C-terminus by PARP9, a component of the PPAR9-DTX3L complex. ADP-ribosylation requires processing by E1 and E2 enzymes and prevents ubiquitin conjugation to substrates such as histones.
Ubiquitin
(Microbial infection) Mono-ADP-ribosylated at Thr-66 by the C.violaceum CteC virulence factor. ADP-ribosylation causes the shutdown of polyubiquitin synthesis and disrupts the recognition and reversal of polyubiquitin.