Muscle-specific transcriptional regulation of the slowpoke Ca(2+)-activated K(+) channel gene.
Transcriptional regulation of the Drosophila slowpoke calcium-activated potassium channel gene is complex. To date, five transcriptional promoters have been identified, which are responsible for slowpoke expression in neurons, midgut cells, tracheal cells, and muscle fibers. The slowpoke promoter called Promoter C2 is active in muscles and tracheal cells. To identify sequences that activate Promoter C2 in specific cell types, we introduced small deletions into the slowpoke transcriptional control region. Using transformed flies, we asked how these deletions affected the in situ tissue-specific pattern of expression. Sequence comparisons between evolutionarily divergent species helped guide the placement of these deletions. A section of DNA important for expression in all cell types was subdivided and reintroduced into the mutated control region, a piece at a time, to identify which portion was required for promoter activity. We identified 55-, 214-, and 20-nucleotide sequences that control promoter activity. Different combinations of these elements activate the promoter in adult muscle, larval muscle, and tracheal cells.
Chang
W M
WM
Section of Neurobiology and Institute for Cellular & Molecular Biology, School of Biological Sciences, University of Texas, Austin, Texas 78712, USA.
Bohm
R A
RA
Strauss
J C
JC
Kwan
T
T
Thomas
T
T
Cowmeadow
R B
RB
Atkinson
N S
NS
D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics; D017124:Conserved Sequence; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D017930:Genes, Reporter; D006651:Histocytochemistry; D051036:Large-Conductance Calcium-Activated Potassium Channels; D008969:Molecular Sequence Data; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D015221:Potassium Channels / Q000235:genetics*; D024681:Potassium Channels, Calcium-Activated; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016415:Sequence Alignment; D017384:Sequence Deletion; D014132:Trachea / Q000378:metabolism; D014170:Transformation, Genetic
D029721:Drosophila Proteins; D051036:Large-Conductance Calcium-Activated Potassium Channels; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; C494844:slo protein, Drosophila