GAP43: The learning protein?

Tue, 01/08/2013 - 10:56

Growth Associated Protein 43 (GAP43), also termed B-50, F1 or P-57, is a neuron-specific cytoplasmic protein encoded by the GAP-43 gene in humans. The expression of GAP 43 is associated with neural development and synaptic plasticity. A high level of GAP43 expression is observed in neuronal growth cones during development, at axonal regeneration after injury and is phosphorylated after long-term potentiation (1).

IF analysis of GAP43 in a mature retinal ganglion cell demonstrating axon outgrowth.

GAP43 protein is considered a crucial component of the axon and presynaptic terminal. GAP-43 knockout mice have been generated for the study of GAP-43 functions. Homozygous knockout of GAP-43 gene (GAP-43-/-) disrupts axonal pathfinding and is generally lethal shortly after birth. Research study showed that mice lacking GAP-43 expression failed to establish the ordered topography in barrel cortex (2). In addition, abnormal ingrowth of serotonergic (5-HT) axons and terminal arborisation were found in GAP-43-/-mice during perinatal period (3).

Significant memory impairment was observed in heterozygous GAP-43 knockout mice (GAP-43+/-) . The level of GAP-43 expression in hippocampal in these mice was reduced by one-half compared with wide-type mice (GAP-43+/+) (4). Interestingly, mice missing a copy of GAP-43 gene (GAP-43+/-) showed biological and behavioral parallels to autism (5). These mice displayed resistance to change, stress-induced hehavioral withdrawal, anxiety and showed low social approach and lack of preference for social novelty, consistent with one of the diagnostic criteria for autism.

GAP-43 is also a component of the centrosome (6). It is a calmodulin-binding IQ motif protein that regulates neuronal cytoskeletal architecture by interacting with F-actin. It was showed that GAP-43 plays a critical role in mitosis and acquisition of neuronal polarity in cerebellar granule neurons. In the absence of GAP-43, differentiating neurons show mislocalization of the centrosome and mitotic spindles, particularly during neurogenic cell division.

  1. PMID: 9023877
  2. PMID: 10430954
  3. PMID: 11978831
  4. PMID: 15390153
  5. PMID: 20707874
  6. PMID: 18235238

Novus Biologicals offers GAP43 reagents for your research needs including:


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