Characterization and Regulation in the Expression of a Gene Coding for the Intermediate Filament Protein Desmin
Using synthetic oligonucleotide probes, we have isolated chicken cDNA clones for the intermediate filament protein desmin. We show that the gene for this protein probably exists as a single copy in the haploid chicken genome and is transcribed into one mature mRNA species of approx 2.4 kilobases. Expression of this mRNA is tissue-specific, as it is present in high abundance in smooth and skeletal muscle but is absent from erythrocytes, spinal cord, and lens cells. A 10- to 20-fold increase in desmin mRNA is observed in myogenic cells upon fusion, which suggests that the level of expression of the desmin gene and the accumulation of desmin filaments during muscle differentiation is regulated at the transcriptional and/or posttranscriptional level but not at the translational level. Hybridization studies and nucleotide sequence comparison of the cDNAs specific for desmin and for other intermediate filament subunits reveal a region that is highly conserved (80%) among different members of the intermediate filament protein gene superfamily, with the exception of the chicken vimentin gene; this gene appears to be less homologous to the genes for the other chicken intermediate filament subunits than the mammalian vimentin gene is to the genes for other mammalian intermediate filament proteins and to the chicken desmin gene.
Additional Information© 1984 by the National Academy of Sciences Communicated by Giuseppe Attardi, July 12, 1984 We thank Dr. Richard Ogden for his help in the preparation of the synthetic oligonucleotide probes and Dr. Costantin Flytzanis for his help with the computer sequence studies. We are grateful to Dr. Nicholas Cowan and his colleagues for communicating their data to us prior to publication. We thank Dr. Eric Davidson for his helpful comments on the manuscript. Adriana Cortenbach, Ilga Lielausis, and Susan Stone provided expert technical assistance. This work was supported by grants from the National Institutes of Health, the National Science Foundation, and the Muscular Dystrophy Association of America and by a Grant-in-Aid from the American Heart Association, Greater Los Angeles Affiliate. Y.G.C. was also supported by postdoctoral fellowships from the Muscular Dystrophy Association and from Proctor and Gamble, and J.N., by a Gordon Ross Foundation Predoctoral Fellowship. E.L. is the recipient of a Research Career Development Award from the National Institutes of Health. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Published - CAPpnas84.pdf