Calcineurin like EF-hand protein 2 (CHP2)

Calcineurin like EF-hand protein 2 (CHP2) is a small, EF-hand calcium-binding protein that serves as an essential cofactor in regulating cellular pH by controlling the activity of plasma membrane Na+/H+ exchangers, particularly the NHE1 isoform[1][3]. CHP2 is structurally characterized by four EF-hand motifs (two that bind calcium), a myristoylation signal, and a conserved nuclear export signal[1]. It shares substantial sequence similarity with calcineurin B, the regulatory subunit of the protein phosphatase calcineurin, and can stimulate calcineurin phosphatase activity under certain conditions[3]. CHP2 is expressed in various tissues, is implicated in proliferation and tumor growth, and was first identified as a tumor-associated antigen. Although not a classical pharmacological target, CHP2's modulation of ion transport and cell signaling pathways makes it significant for cell homeostasis and disease biology[1][3].

Other names

CHP2Hepatocellular carcinoma-associated antigen 520Calcineurin B homologous protein 2Calcineurin homologous protein 2

Not applicable—no drugs directly target CHP2. Its physiological action involves: - Modulating Na+/H+ exchanger activity (not as a drug target but via protein-protein interaction) - Possibly potentiating calcineurin phosphatase activity (protein-level effect, not drug-induced)