Ubiquitin

Ubiquitin is a small protein found in nearly all living cells that plays a crucial role in regulating various cellular processes. Its primary function is to tag other proteins for degradation, essentially marking them for disposal when they're damaged, misfolded, or no longer needed. This tagging process is vital for maintaining cellular health, as it helps control the levels and activity of proteins within the cell. Ubiquitin is also involved in other functions, such as DNA repair and the response to stress, making it essential for normal cell function and overall organismal health.