The CArG promoter sequence is necessary for muscle‐specific transcription of the cardiac actin gene in Xenopus embryos

• Published in: The EMBO journal 1989-04, Vol.8 (4), p.1153-1161
• Main Authors: Mohun, T. J., Taylor, M. V., Garrett, N., Gurdon, J. B.
• Format: Article
• Language: English
• Subjects: Actins - genetics; Animals; Base Sequence; Biological and medical sciences; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; Chromosome Mapping; Cloning, Molecular; DNA - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Molecular and cellular biology; Molecular Sequence Data; Muscles - metabolism; Myocardium - metabolism; Promoter Regions, Genetic; Transcription, Genetic; Xenopus laevis; Xenopus laevis - embryology
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1002/j.1460-2075.1989.tb03486.x

Promoter sequences required for activation of the Xenopus cardiac actin gene in embryonic muscle were analysed by micro‐injecting chimeric actin/beta‐globin genes into the two‐cell Xenopus embryo. Transcription was monitored during subsequent differentiation of embryonic muscle and non‐muscle tissues. The effect of a variety of mutations including internal deletions and linker scan mutations between −64 and −396 within the cardiac actin promoter were tested. This region contains four copies of a conserved motif, the CArG box, common to vertebrate striated muscle acting gene promoters. In the Xenopus cardiac actin gene, the most proximal of these motifs (CArG box 1) located at −80, was essential for muscle‐specific transcription. Other CArG motifs could functionally substitute for CArG box 1 when placed in this position. CArG boxes 3 and 4 bound the same activity in a neurula embryo nuclear extract as CArG box 1 and the amount of this binding activity was constant through early development.