Sequence of cDNAs encoding actin depolymerizing factor and cofilin of embryonic chicken skeletal muscle: two functionally distinct actin-regulatory proteins exhibit high structural homology.
Two actin-regulatory proteins of 19 and 20 kDa are involved in the regulation of actin assembly in developing chicken skeletal muscle. They are homologous with actin depolymerizing factor (ADF) and cofilin, a pH-dependent actin-modulating protein, which were originally discovered in chicken and mammalian brain, respectively. In this study, full-length cDNA clones were isolated by screening a lambda gt11 cDNA library constructed from poly(A+) RNA of embryonic chicken skeletal muscle with the antibodies specific for each protein, and their complete sequences were determined. The chicken cofilin cDNA encoded a protein of 166 amino acids, the sequence of which had over 80% identity with that of porcine brain cofilin. The amino acid sequence of the ADF was 165 amino acids and showed about 70% identity with either chicken or mammalian cofilin, in spite of the fact that ADF and cofilin are functionally distinct. Like chicken and mammalian cofilin, ADF contained a sequence similar to the nuclear transport signal sequence of SV40 large T antigen. ADF and cofilin shared a hexapeptide identical with the amino-terminal sequence of tropomyosin as well as the regions homologous to other actin-regulatory proteins, including depactin, gelsolin, and profilin. The overall nucleotide sequences and Southern blot analysis of genomic DNA, however, indicated that the two proteins were derived from different genes.
Abe
H
H
Department of Biology, Chiba University, Japan.
Endo
T
T
Yamamoto
K
K
Obinata
T
T
D051339:Actin Depolymerizing Factors; D000199:Actins / Q000096:biosynthesis / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002642:Chick Embryo; D004247:DNA / Q000378:metabolism*; D051345:Destrin; D005786:Gene Expression Regulation; D015698:Genomic Library; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D011061:Poly A / Q000235:genetics; D012313:RNA / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013329:Structure-Activity Relationship
D051339:Actin Depolymerizing Factors; D000199:Actins; D051345:Destrin; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D011061:Poly A; D012313:RNA; D004247:DNA