Analysis of the proenkephalin second messenger-inducible enhancer in rat striatal cultures.
We have previously shown that in cell extracts from rat striatum, cyclic AMP response element (CRE) binding protein (CREB), rather than AP-1 proteins, preferentially interacts with the CRE-2 element of the proenkephalin second messenger-inducible enhancer, even under conditions in which AP-1 proteins are highly induced. Here we use primary striatal cultures to permit a more detailed analysis of CRE-2 function and protein binding in relevant neural cell types. By transfection we find that in primary striatal cultures, as in transformed cell lines, the CRE-1 and CRE-2 elements are required for significant induction by cyclic AMP. We report that cyclic AMP induction of the proenkephalin gene in striatal cultures is protein synthesis independent, excluding a role for newly synthesized proteins like c-Fos. We also show that cyclic AMP induces CREB phosphorylation and that phosphorylated CREB interacts strongly with CRE-2 and weakly with CRE-1. The predominant protein bound to CRE-1 is not CREB, however, and remains to be identified. Despite some prior predictions, we do not find a role for c-Fos in cyclic AMP regulation of proenkephalin gene expression in neurons.
Konradi
C
C
Laboratory of Molecular and Developmental Neuroscience, Massachusetts General Hospital, Charlestown 02129, USA.
Cole
R L
RL
Green
D
D
Senatus
P
P
Leveque
J C
JC
Pollack
A E
AE
Grossbard
S J
SJ
Hyman
S E
SE
D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone / Q000494:pharmacology; D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D000242:Cyclic AMP / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D004745:Enkephalins / Q000235:genetics*; D005333:Fetus; D016762:Genes, fos; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015290:Second Messenger Systems; D018808:Transcription Factor AP-1 / Q000378:metabolism
D017362:Cyclic AMP Response Element-Binding Protein; D004745:Enkephalins; D011498:Protein Precursors; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; C029992:proenkephalin; D005576:Colforsin; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; D019830:Adenosine-5'-(N-ethylcarboxamide); D000242:Cyclic AMP; D000241:Adenosine