Q13616

CUL1 also known as Cullin1 is the mammalian homolog of yeast Cdc53, is an integral component of the E3 ubiquitin ligase complex designated SCF. CUL1 plays a crucial role in the ubiquitin-proteasome pathway, functioning as a key component of the SCF (Skp1/CUL1/F-box protein) E3 ubiquitin ligase complex, which is essential for the targeted degradation of specific proteins. This process is vital for regulating the cell cycle, as CUL1 mediates the ubiquitination and subsequent degradation of critical cell cycle regulators such as cyclin D, p21, and cyclin E. By controlling the levels of these proteins, CUL1 ensures proper cell cycle progression and prevents uncontrolled cell proliferation, which is a hallmark of cancer. Additionally, CUL1 interacts with various F-box proteins, such as Skp2, to determine substrate specificity, highlighting CUL1′s importance in maintaining cellular homeostasis and responding to cellular signals.