Specific agrin isoforms induce cAMP response element binding protein phosphorylation in hippocampal neurons.

Published

Journal Article

The synaptic basal lamina protein agrin is essential for the formation of neuromuscular junctions. Agrin mediates the postsynaptic clustering of acetylcholine receptors and regulates transcription in muscles. Agrin expression is not restricted to motor neurons but can be demonstrated throughout the CNS. The functional significance of agrin expression in neurons other than motor neurons is unknown. To test whether agrin triggers responses in neurons that lead to the activation of transcription factors, we have analyzed phosphorylation of the transcriptional regulatory site serine 133 of the transcription factor CREB (cAMP response element binding protein) in primary hippocampal neurons. Our results indicate that the neuronal (Ag4,8), but not the non-neuronal (Ag0,0), isoform of agrin induces CREB phosphorylation in hippocampal neurons. The kinetics of agrin- and BDNF-induced CREB phosphorylation are similar: peak levels are reached in minutes and are strongly reduced 2 hr later. Neuronal responses to agrin require extracellular calcium, and, in contrast to tyrosine kinase inhibitors, the specific inhibition of protein kinase A (PKA) does not affect agrin-evoked CREB phosphorylation. Our results show that hippocampal neurons specifically respond to neuronal agrin in a Ca2+-dependent manner and via the activation of tyrosine kinases.

Full Text

Duke Authors

Cited Authors

  • Ji, RR; Böse, CM; Lesuisse, C; Qiu, D; Huang, JC; Zhang, Q; Rupp, F

Published Date

  • December 1, 1998

Published In

Volume / Issue

  • 18 / 23

Start / End Page

  • 9695 - 9702

PubMed ID

  • 9822730

Pubmed Central ID

  • 9822730

International Standard Serial Number (ISSN)

  • 0270-6474

Language

  • eng

Conference Location

  • United States