Alkaline phosphatase multi-tasks in the brain – Université Toulouse

Abstract : Introduction: There are several genes for alkaline phosphatase (AP). One of them codes for TNAP (Tissue Non-specific Alkaline Phosphatase). It is a ubiquitous ectoenzyme located in different tissues in the body. In the brain, this enzyme is GPI anchored on the neuronal membrane, especially on node of Ranvier and synapses (Fonta et al., 2005). Mutations of the TNAP gene are responsible for hypophosphatasia, a rare disease characterized by defective bone mineralization (Millan, 2006) caused by pyrophosphate accumulation. In the severe form, hypophosphatasia is associated with epileptic seizures (Whyte, 1995). This neurological disorder could be explained by a decrease in GABA level due to lack of pyridoxal 5’phosphate (PLP) dephosphorylation