What does ubiquitin mean?

Definitions for ubiquitin
ubiq·ui·tin

This dictionary definitions page includes all the possible meanings, example usage and translations of the word ubiquitin.


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Wiktionary

  1. ubiquitinnoun

    A small polypeptide present in the cells of all eukaryotes; it plays a part in modifying and degrading proteins

Wikipedia

  1. Ubiquitin

    Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ubiquitously. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. Four genes in the human genome code for ubiquitin: UBB, UBC, UBA52 and RPS27A.The addition of ubiquitin to a substrate protein is called ubiquitylation (or, alternatively, ubiquitination or ubiquitinylation). Ubiquitylation affects proteins in many ways: it can mark them for degradation via the proteasome, alter their cellular location, affect their activity, and promote or prevent protein interactions. Ubiquitylation involves three main steps: activation, conjugation, and ligation, performed by ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s), respectively. The result of this sequential cascade is to bind ubiquitin to lysine residues on the protein substrate via an isopeptide bond, cysteine residues through a thioester bond, serine and threonine residues through an ester bond, or the amino group of the protein's N-terminus via a peptide bond.The protein modifications can be either a single ubiquitin protein (monoubiquitylation) or a chain of ubiquitin (polyubiquitylation). Secondary ubiquitin molecules are always linked to one of the seven lysine residues or the N-terminal methionine of the previous ubiquitin molecule. These 'linking' residues are represented by a "K" or "M" (the one-letter amino acid notation of lysine and methionine, respectively) and a number, referring to its position in the ubiquitin molecule as in K48, K29 or M1. The first ubiquitin molecule is covalently bound through its C-terminal carboxylate group to a particular lysine, cysteine, serine, threonine or N-terminus of the target protein. Polyubiquitylation occurs when the C-terminus of another ubiquitin is linked to one of the seven lysine residues or the first methionine on the previously added ubiquitin molecule, creating a chain. This process repeats several times, leading to the addition of several ubiquitins. Only polyubiquitylation on defined lysines, mostly on K48 and K29, is related to degradation by the proteasome (referred to as the "molecular kiss of death"), while other polyubiquitylations (e.g. on K63, K11, K6 and M1) and monoubiquitylations may regulate processes such as endocytic trafficking, inflammation, translation and DNA repair.The discovery that ubiquitin chains target proteins to the proteasome, which degrades and recycles proteins, was honored with the Nobel Prize in Chemistry in 2004.

Wikidata

  1. Ubiquitin

    Ubiquitin is a small regulatory protein that has been found in almost all tissues of eukaryotic organisms. It directs proteins to compartments in the cell, including the proteasome which destroys and recycles proteins. Ubiquitin can be attached to proteins and label them for destruction. This discovery won the Nobel Prize for chemistry in 2004. Ubiquitin tags can also direct proteins to other locations in the cell, where they control other protein and cell mechanisms.

U.S. National Library of Medicine

  1. Ubiquitin

    A highly conserved 76-amino acid peptide universally found in eukaryotic cells that functions as a marker for intracellular PROTEIN TRANSPORT and degradation. Ubiquitin becomes activated through a series of complicated steps and forms an isopeptide bond to lysine residues of specific proteins within the cell. These "ubiquitinated" proteins can be recognized and degraded by proteosomes or be transported to specific compartments within the cell.

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Numerology

  1. Chaldean Numerology

    The numerical value of ubiquitin in Chaldean Numerology is: 9

  2. Pythagorean Numerology

    The numerical value of ubiquitin in Pythagorean Numerology is: 5

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Translations for ubiquitin

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"ubiquitin." Definitions.net. STANDS4 LLC, 2025. Web. 15 Feb. 2025. <https://www.definitions.net/definition/ubiquitin>.

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