Abstract
The purpose of this study was to delineate the alpha-actin regulatory elements and transcription factors that are responsible for conferring stretch-overload responsiveness during hypertrophy of the anterior latissimus dorsi (ALD) muscle of young chickens by weighting one wing. Minimal promoter constructs were evaluated by direct injection into the ALD, which demonstrated that both serum response element 1 (SRE1) and the transcriptional enhancer factor 1 (TEF-1) elements were sufficient for increased expression during stretch overload. A mutated SRE1 prevented expression in both basal and stretched ALD muscles, whereas a mutated TEF-1 element reduced actin promoter function in both control and stretched muscles. The serum response factor (SRF)-SRE1 binding complex demonstrated faster migration in mobility shift assays from day 3-and day 6-stretched ALD nuclear extracts relative to their control. TEF-1 binding was qualitatively increased in stretched extracts at day 3 but not day 6 of stretch overload. Skeletal alpha-actin mRNA accumulated from day 3 to day 6 of stretch overload. These data demonstrate that SRE1 is necessary and sufficient for stretch-overload responsiveness from the skeletal alpha-actin promoter and that the SRF-SRE1 binding complex migrates faster in stretched nuclear extracts of hypertrophied relative to control extracts from intact ALD muscles of chickens.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
