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Heat‐shock proteins are associated with hnRNA in Drosophila melanogaster tissue culture cells
Author(s) -
Kloetzel PeterM.,
Bautz Ekkehard K.F.
Publication year - 1983
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1983.tb01488.x
Subject(s) - biology , drosophila melanogaster , heat shock protein , microbiology and biotechnology , precursor mrna , genetics , rna , gene , rna splicing
Ribonucleoprotein complexes of Drosophila melanogaster Kc tissue culture cells grown at 24°C or heat‐shocked at 37°C were cross‐linked in vivo by u.v. irradiation. Cross‐linked heterogeneous nuclear ribonucleoprotein (hnRNP) complexes were fractionated by oligo(dT)‐cellulose chromatography and CsCI density centrifugation. The hnRNP complexes of both 24°C and 37°C culture cells possess buoyant densities in CsCI between ϱ = 1.38 g/cm ‐3 and 1.43 g/cm ‐3 . The 35 S‐labelled proteins bound to the hnRNA of 37°C culture cells correspond in mol. wt. to the so‐called heat‐shock proteins of 70 K, 68 K, 27 K, 26 K, 23 K and 22 K. The 70 K and 68 K proteins are also present in hnRNP complexes of 24°C culture cells. In addition, several other Drosophila hnRNPs of 140 K, 56 K, 45 K, 43 K, 38 K, 37 K and 34 K, whose synthesis is strongly repressed under heat‐shock conditions, could be identified. The results demonstrate that the so‐called heat‐shock proteins possess a function as RNPs.