Estrogen-induced changes in chick oviduct membrane glycoproteins

Abstract

Membrane protein and glycoprotein changes during estrogen-induced differentiation of the chick oviduct were studied. Membrane preparations from chicks treated with diethylstilbestrol for 3, 6, 10, and 20 days; from chicks treated with hormone for 10 days and then withdrawn for 2 days; and from mature hens were incubated with either GDP-[14C]Man or GDP-[3H]Man. Double label analysis of proteins using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicates that labeling of proteins with apparent molecular weights of 91,000 and 57,000 is enhanced upon diethylstilbestrol treatment. The effect is reversed upon hormone withdrawal. Analysis of [14C]Man-proteins by SDS-PAGE and fluorography reveals at least 18 labeled proteins, confirms the double label gel results, and shows changes in three additional proteins. Estrogen-induced changes in membrane proteins and glycoproteins were also studied by Coomassie blue staining, periodic acid-Schiff staining, and autoradiography of 125I-concanavalin A binding following SDS-PAGE. Changes are observed in at least 9 Coomassie blue, 7 periodic acid-Schiff and 13 125I-concanavalin A bands. Some proteins are enhanced by estrogen treatment and are diminished upon withdrawal, whereas other proteins are diminished by estrogen treatment and are enhanced by withdrawal. Hen oviduct membrane preparations were labeled with combinations of UDP-GlcNAc, GDP-Man, and UDP-Glc. Tunicamycin inhibits incorporation of [3H]Man and [14C]GlcNAc into protein by 84% and 65%, respectively. SDS-PAGE reveals that transfer of GlcNAc to a 36,000 protein is the least sensitive to tunicamycin. SDS-PAGE of proteins labeled by incubation with GDP-[14C]Man and UDP-[3H]Glc indicate that the presence of Glc does not alter the typical Man-protein-labeling pattern and processing of Glc from individual acceptors uniform.