Casein kinase I isoform alpha

Casein kinase I isoform alpha (CKI-alpha), encoded by CSNK1A1, is a serine/threonine kinase that phosphorylates numerous substrates, particularly acidic proteins such as caseins (UniProt: P48729). The enzyme plays roles in Wnt signaling through phosphorylation of CTNNB1, potential regulation of circadian clock proteins (PER1/PER2), chromosome segregation, and epithelial cell migration via keratin cytoskeleton dynamics. Additionally, CKI-alpha acts as a positive regulator of mTORC1/mTORC2 signaling and inhibits NLRP3 inflammasome assembly.

CKI-alpha has not been annotated with primary disease associations in UniProt but is implicated in multiple cellular pathways relevant to neurological function, including Wnt signaling and mTOR metabolism. Its involvement in inflammasome regulation suggests potential relevance to neuroinflammatory processes.

In Alzheimer's disease, CKI-alpha is significantly upregulated in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of +0.22 (Chaparral AD proteomics). This elevation was observed in a quantitative mass spectrometry study of subcellular fractions from AD brain, suggesting a potential role in disease-associated cellular dysregulation, though the functional consequences of this upregulation remain to be determined.