ubiquitin

u·biq·ui·tin (y-bkw-tn)

n.

A polypeptide found in all eukaryotic cells, including plant cells, that participates in a variety of cellular functions including protein degradation.

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ubiquitin (yōōˈ·biˑ·kwi·tin),

n a 76-amino acid polypeptide from modification of histones; present in yeast and in most eukaryotic cells.

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ubiquitin

heat shock (cell stress) protein present in mammalian cytosol; attaches to other cytosolic proteins and marks them for degradation either by specific proteases or by lysosomal enzymes.