Previous Article | Next Article ![]()
Molecular and Cellular Biology, August 2008, p. 5061-5070, Vol. 28, No. 16
0270-7306/08/$08.00+0 doi:10.1128/MCB.00578-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.
B 
Lineberger Comprehensive Cancer Center,1 Curriculum in Genetics and Molecular Biology,2 Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 275993
Received 9 April 2008/ Returned for modification 21 May 2008/ Accepted 27 May 2008
Glutamate is a critical neurotransmitter of the central nervous system (CNS) and also an important regulator of cell survival and proliferation. The binding of glutamate to metabotropic glutamate receptors induces signal transduction cascades that lead to gene-specific transcription. The transcription factor NF-
B, which regulates cell proliferation and survival, is activated by glutamate; however, the glutamate receptor-induced signaling pathways that lead to this activation are not clearly defined. Here we investigate the glutamate-induced activation of NF-
B in glial cells of the CNS, including primary astrocytes. We show that glutamate induces phosphorylation, nuclear accumulation, DNA binding, and transcriptional activation function of glial p65. The glutamate-induced activation of NF-
B requires calcium-dependent I
B kinase
(IKK
) and IKKβ activation and induces p65-I
B
dissociation in the absence of I
B
phosphorylation or degradation. Moreover, glutamate-induced IKK preferentially targets the phosphorylation of p65 but not I
B
. Finally, we show that the ability of glutamate to activate NF-
B requires cross-coupled signaling with the epidermal growth factor receptor. Our results provide insight into a glutamate-induced regulatory pathway distinct from that described for cytokine-induced NF-
B activation and have important implications with regard to both normal glial cell physiology and pathogenesis.
Published ahead of print on 9 June 2008.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»