Protein: UBI4P_YEAST
Polyubiquitin
SUBCELLULAR LOCATION: Cytoplasm (By similarity). Nucleus (By similarity). MISCELLANEOUS: Ubiquitin is encoded by 4 different genes. UBI1 and UBI2 genes code for a single copy of ubiquitin fused to the ribosomal proteins L40. UBI3 is a polyprotein with one copy of ubiquitin fused to ribosomal protein S37. UBI4 is a polyprotein containing 5 exact head to tail repeats of ubiquitin.
SIMILARITY: Belongs to the ubiquitin family.
SIMILARITY: Contains 5 ubiquitin-like domains.
GENE SYNONYMS: SCD2.
COPYRIGHT: Protein annotation is derived from the UniProt Consortium (http://www.uniprot.org/). Distributed under the Creative Commons Attribution-NoDerivs License.
Organism:
- Saccharomyces cerevisiae
Gene Symbol:
- UBI4
Synonyms:
- Ubiquitin
Links:
Stable Link:
- Link to this page
Link to this pagePaste link in email or IM:Paste HTML to embed in website:
FUNCTION: 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 lysosomal degradation; 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, and DNA-damage responses. 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 (By similarity). more...