Two independent promoters as well as 5' untranslated regions regulate Dd ras expression in Dictyostelium.
The Dd ras gene produces three transcripts during Dictyostelium development. The largest transcript (L-) can be induced by external addition of cAMP even in cells prevented from aggregating, whereas shorter transcripts (S1- and S2-) expression requires cell aggregate formation. We show the presence of two independent promoters for L- and S-transcripts by deletion analysis of Dd ras fragments fused to CAT reporter genes reintroduced in Dictyostelium. A direct repeat upstream of S-transcript start sites which seems involved in S-promoter function, modulates also L-RNA accumulation. Furthermore removal of sequences between this repeat and the AUG protein start codon reduces the level of L-transcripts in aggregates. This study allowed to uncover the intricate pattern of sequences participating in the regulation of Dd ras expression.
Louvion
J F
JF
Swiss Institute for Experimental Cancer Research, ISREC, CH-1066 Epalinges.
Scholder
J C
JC
Pinaud
S
S
Reymond
C D
CD
D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D000242:Cyclic AMP / Q000378:metabolism; D004247:DNA / Q000235:genetics; D004023:Dictyostelium / Q000235:genetics*; D005800:Genes, Fungal; D011905:Genes, ras; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D014158:Transcription, Genetic
D004247:DNA; D000242:Cyclic AMP; D015500:Chloramphenicol O-Acetyltransferase