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.
Department of Biology, Chiba University, Japan.
H
H
Abe
T
T
Endo
K
K
Yamamoto
T
T
Obinata
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