Stress proteins in the human endometrium and decidua

Protein synthesis in response to heat shock was induced in the proliferative and secretory human endometrium as well as in human decidua during a 2-h incubation period at 41 degrees C. A major 70 K stress protein and two minor stress proteins of 88 and 94 K were detected after [35S]methionine incorporation followed by SDS polyacrylamide gel electrophoretic separation and autoradiography of dried gels. Two dimensional isoelectric focusing followed by fluorography showed the major 70 K stress protein to consist of at least six polypeptides of pH 4.6 to 5.5, the 88 K to consist of at least four polypeptides, of pH 5.5 to 6.0, and the 94 K to consist of at least three polypeptides of pH 4.6 to 5.2. Stress proteins in the human endometrium and decidua may prove to be of physiological significance in reproductive events.