CK1α (Casein Kinase 1 alpha)

Class

Small molecule molecular glue degrader

Pathway

Targeted protein degradation via ubiquitin-proteasome system

CK1α (casein kinase 1 alpha) is an enzyme that adds phosphate groups to other proteins, helping regulate the Wnt/β-catenin signaling pathway, the stability of the tumor-suppressor protein p53, and other processes tied to cell growth and survival. Instead of blocking CK1α's catalytic activity directly, a molecular glue degrader works by reshaping a surface of the protein so that it is pulled into contact with a cellular ubiquitin ligase complex, an assembly that normally tags damaged or unwanted proteins for destruction. Once bound, CK1α is marked with ubiquitin and broken down by the proteasome, the cell's protein-disposal machinery. Because the whole protein is eliminated rather than just one function being blocked, both its enzymatic and structural roles are removed. This strategy is particularly relevant to certain blood cancers in which chromosomal loss has already reduced the normal gene dose of CK1α; further depletion can drive these already-vulnerable cells past a survival threshold while leaving cells with a full gene complement relatively unaffected. More broadly, CK1α-dependent signaling is implicated in diseases involving abnormal Wnt pathway activity and disrupted cell-cycle regulation.