Calcium/calmodulin-dependent protein kinase type II subunit beta

CAMK2B encodes calcium/calmodulin-dependent protein kinase type II subunit beta, a serine/threonine kinase that functions in neuronal signaling after Ca²⁺/calmodulin binding and autophosphorylation (UniProt: Q13554). Beyond its catalytic role in phosphorylating substrates like STAT1 and phospholamban, the protein serves a critical structural function by bundling actin filaments in a kinase-independent manner, essential for dendritic spine formation, synaptic plasticity, and long-term potentiation in hippocampal neurons.

CAMK2B is widely expressed and participates in skeletal muscle calcium homeostasis and neuronal migration during development (UniProt: Q13554). A dominant mutation in CAMK2B causes autosomal dominant intellectual developmental disorder 54 (MRD54; UniProt: Q13554), underscoring its role in neural development and cognitive function.

CAMK2B shows elevated expression in post-mortem Alzheimer's disease brain tissue compared to age-matched controls, with a mean log2 fold-change of +0.92 (Chaparral AD proteomics). This upregulation may reflect compensatory synaptic plasticity mechanisms or alterations in calcium signaling pathways implicated in neurodegeneration, though the functional significance of increased CAMK2B in AD pathology requires further investigation.