Calbindin 1 (CALB1)

Calbindin 1 is a 28 kDa calcium-binding protein encoded by the CALB1 gene and characterized by its six EF-hand domains (helix-loop-helix motifs), four of which coordinate calcium ions[1][2][3][4]. It acts as both a calcium buffer and sensor, contributing to intracellular calcium homeostasis in various tissues, notably the brain and kidney[1][2]. Calbindin 1 is highly expressed in neurons, especially cerebellar Purkinje cells, and serves as a marker for cell differentiation and maturity[3]. Its biological role includes buffering calcium influx after activation of glutamate receptors and conferring neuroprotection by reducing excitotoxic damage[1][3]. Loss of calbindin 1 expression has been linked to neurodegenerative diseases such as Huntington disease[1]. Calbindin 1 itself is not a direct therapeutic target, but its interaction with proteins such as inositol monophosphatase (IMPase) may have relevance for conditions like bipolar disorder, where IMPase activity is affected by lithium treatment[4]. Calbindin 1 is often used as a biomarker for distinct neuronal populations and disease states.

Other names

Calbindin-D28kCalbindinCALB128 kDa calcium-binding protein

Not applicable (not a direct drug target). Increases activity of IMPase via protein-protein interaction, potentially affecting inositol signaling relevant for some neurologic disorders[4].