New approaches to understanding the regulation of ER-subcompartment dynamics by using experimental techniques in endocrinology.

点击翻译按钮获取中文摘要

To examine the morphological and functional characteristics of the ER in vivo, we analyzed the ER changes of male rat pituitary gonadotropes during sustained treatment with various GnRH analogs. In pituitary gonadotropes at 1 day after subcutaneous implantation of osmotic pumps filled with a GnRH agonist, leuprolide acetate, patch-like accumulations of two representative chaperons, calnexin and BiP appeared. Similar changes were observed under the condition of another GnRH agonist, buserelin. Observation at the electron microscopic level could reveal atypical accumulations of the ER chaperones in anomalous clusters of tubuloreticular membranes within the stimulated gonadotrope. In addition to the chaperones, HRD1, an E3 ligase related to ER associated degradation (ERAD), is localized to the ER patches and surrounding membranes in the stimulated gonadotropes. These findings indicate the anomalous ER clusters provide a scaffold for quality control of secretion proteins in gonadotropes.