GAP43/A0215

Growth-associated protein 43 (GAP43), also known as neuromodulin or A0215, is involved in differentiation and growth of nerve cells.

Growth-associated protein 43 (GAP43), also known as neuromodulin or A0215, is involved in differentiation and growth of nerve cells. It is selectively expressed in the nerve tissue and is especially concentrated in growth cones. The GAP43 protein contains an IQ motif essential for interaction with calmodulin, an important calcium-binding protein. Protein kinase C phosphorylates GAP43 and over-expression of phosphorylated GAP43 protein is known to affect synaptic plasticity. Targeted disruption of the GAP43 gene in mice drastically reduces survival of homozygous mutant pups, with only 10% surviving after weaning. Characteristic phenotypes of GAP43-deficient mice are impaired development of the optic nerve and abnormal mapping of interneuronal connections in the cortex. Decrease of GAP43 immunoreactivity was demonstrated in dentate gyrus of schizophrenic patients. A significant increase in the amount of GAP43 protein was noted in the postmortem hippocampus of Alzheimer’s disease patients.