Molecular cloning of cDNA sequences coding for the major (beta-, gamma-, delta- and epsilon-) heat-shock polypeptides...

The method of differential in situ colony hybridisation and the technique of two-dimensional gel electrophoresis of polypeptides synthesized in vitro by mRNAs that hybridise specifically to recombinant plasmids bound to filter discs, have been used to isolate two cDNA HeLa heat-shock clones. Each of these two clones contains the plasmid pBR322 with a cDNA fragment of about 0.3 kb inserted into the PstI site. The two fragments hae different restriction maps. Whilst one of the recombinant plasmids, pHS2, contains a cDNA sequence that hybridises to mRNA coding for the HeLa heat-shock gamma-polypeptide, the other, pHS6, cross-hybridises with mRNAs that code for the HeLa heat-shock beta-, delta- and epsilon-polypeptides.