Positive- and negative-acting promoter sequences regulate cell type-specific expression of the rat synapsin I gene.
The phosphoprotein synapsin I is expressed exclusively in neuronal cells. We are interested in elucidating the promoter sequences involved in cell type-specific expression of the synapsin I gene. The PC12 cell line expresses the 3.4 kb and 4.5 kb synapsin I mRNAs and is used to analyze cell type-specific gene expression. A series of deletion fragments of the rat synapsin I gene promoter were fused to the promoterless reporter gene encoding bacterial chloramphenicol acetyltransferase (CAT) for transfection analysis in PC12 cells and in HeLa cells, which do not express the gene. A -349 bp to +110 bp rat synapsin I promoter fragment contains a positive regulator, shown to be 33-times more active in PC12 cells than HeLa cells. Transfection of reporter plasmids containing up to 4.4 kb of rat synapsin I gene promoter sequences exhibit significantly reduced CAT activity in PC12 cells. The reduction in CAT expression was attributed to a negative regulator located between -349 bp and -1341 bp in the rat synapsin I promoter. Our results suggest that both positive and negative-acting sequence elements regulate cell type-specific expression of the rat synapsin I gene.
Howland
D S
DS
Department of Neurology, University of Massachusetts Medical School, Worcester 01655.
Hemmendinger
L M
LM
Carroll
P D
PD
Estes
P S
PS
Melloni
R H
RH
DeGennaro
L J
LJ
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000502:physiology; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000502:physiology; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016716:PC12 Cells; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016704:Synapsins / Q000235:genetics*; D014162:Transfection
D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D016704:Synapsins; D015500:Chloramphenicol O-Acetyltransferase