Journal of Neuroscience, Vol 14, 1584-1595, Copyright © 1994 by Society for Neuroscience
NMDA receptor activation in differentiating cerebellar cell cultures regulates the expression of a new POU gene, Cns-1
RF Bulleit, H Cui, J Wang and X Lin
Department of Pharmacology, University of Maryland School of Medicine, Baltimore 21201.
POU/homeobox genes encode transcription regulatory proteins that are
important in defining cellular phenotypes. Expression of these genes may be
critical for to the regulation of CNS cellular differentiation. We have
identified a cDNA corresponding to a new member of the POU/homeobox gene
family. Expression of RNA encoded by this new gene occurs predominantly in
the CNS. Thus, this new gene was designated Cns- 1. Cns-1 transcripts are
expressed in differentiating cells cultured from the early postnatal
cerebellum. Treatment of these cultured cells with NMDA results in an
increase in the level of Cns-1 RNA. This increase is blocked by
simultaneous treatment with the specific NMDA receptor antagonist
amino-5-phosphonovaleric acid. Continued activation of the NMDA receptor
allows maintenance of this new steady state level of Cns-1 mRNA for at
least 5 d in these cultured cells. A transcription runoff assay suggests
that this increase in the level of RNA is due, at least in part, to an
increase in transcription from the Cns-1 gene. The NMDA-induced increase in
Cns-1 mRNA was reduced by pretreatment with calcium chelators EGTA or
1,2-bis(2-aminophenoxy)ethane-N,N,N',N'- tetraacetic acid (BAPTA)
tetrakis(acetoxymethyl). These studies suggest that specific activation of
the NMDA receptor in cultures of differentiating cerebellar cells increases
Cns-1 gene expression and that calcium entry through the NMDA channel may
be required for this response. This change in Cns-1 expression may modify
phenotypic characteristics of these cultured cells.