Choline Kinase α/CHKA Recombinant Rabbit mAb (S-4422-31)

Choline kinase alpha (CHKA or ChoKα) is the first key enzyme in the Kennedy pathway of phosphatidylcholine biosynthesis, catalyzing the phosphorylation of free choline to phosphocholine in the cytoplasm, a step essential for maintaining cell membrane structural integrity and supporting cell proliferation. The human gene encoding CHKA is located on chromosome 11q13.2, spans approximately 69 kb, and through alternative splicing produces two isoforms of 457 and 439 amino acid residues; its active form functions as a homo- or heterodimer and requires ATP and Mg²⁺ for catalytic activity. Structural biology studies have revealed that its active center contains an ATP-binding pocket formed by two lobes and a deep hydrophobic groove in the C-terminal domain serving as the choline-binding site, and it exhibits a unique double-displacement catalytic mechanism in which the γ-phosphate group of ATP is first transferred to the enzyme itself to form a phosphorylated enzyme intermediate, which then transfers the phosphate to choline. In addition to catalyzing choline phosphorylation, CHKA also retains ethanolamine kinase activity, capable of phosphorylating ethanolamine and participating in phosphatidylethanolamine synthesis. In cancer biology, CHKA is considered an important oncogene, overexpressed in approximately 40–60% of human tumors (such as breast cancer, lung cancer, colorectal cancer, and glioma), and its high expression is closely associated with poor patient prognosis. Its oncogenic mechanisms not only involve providing phospholipid precursors for the robust membrane synthesis of tumor cells but also include its enzymatic product phosphocholine exerting mitogenic signaling effects, as well as non-enzymatic functions through protein-protein interactions (such as binding to the epidermal growth factor receptor EGFR and activating downstream MAPK signaling pathways) to drive malignant tumor progression. Consequently, CHKA has become a highly promising anti-tumor drug target, with specific inhibitors already entering clinical trials.