Induction of the estrogen-regulated "24K" protein by heat shock.

We have previously demonstrated an estrogen-regulated protein, termed 24K, in human breast cancer cell lines and human tumor biopsies. The presence of the protein correlates well with the presence of steroid hormone receptors. We have cloned a partial complementary DNA to 24K and show that the nucleotide and deduced amino acid sequence contains a striking homology to the low molecular weight heat shock proteins of Drosophila and the mammalian alpha-crystallins.