Regulation of skeletal alpha-actin promoter in young chickens during hypertrophy caused by stretch overload.
Anterior latissimus dorsi (ALD) muscles of 3-wk-old male chickens were injected with plasmids containing various lengths of the chicken skeletal alpha-actin promoter (ranging from -2,090 to -77 relative to the transcription start site) driving luciferase. Hypertrophy of the left ALD muscle was induced by attaching a weight (11% of body wt) to the left wing of each chicken, with the unweighted contralateral wing serving the control. Six days of stretch overload significantly increased muscle mass 110%. Luciferase activity from the -2,090 actin-luciferase chimeric gene increased 127% compared with the contralateral control ALD muscle. Luciferase activities driven by the -424, -202, and -99 actin promoters were 179, 134, and 378% higher, respectively, in the stretched ALD muscle than in the contralateral control ALD muscle. Luciferase activity from the -77 deletion construct was not different between stretched and control muscles. These data indicate that the gene region responding to stretch is downstream of -99 and imply, but do not conclusively prove, that the region between -99 and -77, which contains serum response element 1, contributes to the stretch-induced increase in skeletal alpha-actin promoter activity in the ALD muscle.
Carson
J A
JA
Department of Physiology and Cell Biology, University of Texas-Houston Health Science Center, USA.
Yan
Z
Z
Booth
F W
FW
Coleman
M E
ME
Schwartz
R J
RJ
Stump
C S
CS
D000199:Actins / Q000235:genetics*; D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight; D002478:Cells, Cultured; D002645:Chickens; D002678:Chimera; D005786:Gene Expression Regulation; D006984:Hypertrophy; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology*; D009929:Organ Size; D011401:Promoter Regions, Genetic; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
D000199:Actins; D012333:RNA, Messenger; D012313:RNA