title: Expression of genes encoding the transcription factor SRF during early development of Xenopus laevis: identification of a CArG box-binding activity as SRF.
abstract: cDNA clones encoding the sequence-specific DNA binding protein, serum response factor (SRF), have been isolated from a Xenopus laevis neurula library and their nucleotide sequence determined. The Xenopus SRF (SRFX) gene produces multiple-sized transcripts, present at 10(5) copies per unfertilized egg. A similar level is detected in the embryo during early cleavage, but SRFX transcripts accumulate rapidly following gastrulation. The protein they encode is similar in sequence to human SRF in its central and carboxy-terminal regions, but possesses a divergent amino-terminal portion. We have previously described a Xenopus embryo sequence-specific binding activity that recognized the CArG motif of the cardiac actin gene promoter. Here we show that the DNA-binding characteristics of synthetic SRFX are indistinguishable from those of the embryo factor. Moreover, antiserum raised against the synthetic SRFX recognizes this factor. Together, these results establish that the same factor binds to elements required for constitutive transcription in Xenopus oocytes, muscle-specific gene expression in Xenopus embryos and serum-responsive transcription in cultured amphibian cells.
authors.affiliation: Laboratory of Developmental Biochemistry, National Institute for Medical Research, Mill Hill, London, UK.
authors.forename: T J
authors.initials: TJ
authors.lastname: Mohun
authors.forename: A E
authors.initials: AE
authors.lastname: Chambers
authors.forename: N
authors.initials: N
authors.lastname: Towers
authors.forename: M V
authors.initials: MV
authors.lastname: Taylor
mesh_terms: D000375:Aging; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000502:physiology*; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010063:Ovum / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D026362:Serum Response Factor; D012984:Software; D014982:Xenopus laevis
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D026362:Serum Response Factor; D004247:DNA