Regulation of alpha 2-macroglobulin by luteinizing hormone and prolactin during cell differentiation in the rat ovary.
Alph alpha 2-macroglobulin (alpha 2M), a protease inhibitor which also binds growth factors and cytokines, is temporally expressed in association with remodelling phenomena in the ovary: ovulation and luteinization. Specific hormonal, cellular, subcellular, and molecular events regulating alpha 2M mRNA and protein have been analyzed during follicular growth, ovulation, and luteinization using complementary in vivo and in vitro models. Data demonstrate that alpha 2M mRNA and protein are synthesized in thecal cells of developing follicles in response to low levels of LH. Conversely, alpha 2M mRNA and protein are only synthesized by granulosa cells of follicles that have been stimulated to luteinize either in vivo by the LH surge or in vitro by FSH and testosterone and are also exposed to PRL. The obligatory requirement for PRL is specific; associated with increased numbers of PRL-binding sites; mediated by time-dependent appearance of alpha 2M in the endoplasmic reticulum (12 h), Golgi apparatus (24 h), and secretion vesicles (48 h); and involves in part increased transcription of the alpha 2M gene.
Gaddy-Kurten
D
D
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
Richards
J S
JS
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002458:Cell Fractionation; D002478:Cells, Cultured; D005260:Female; D005498:Follicular Phase / Q000235:genetics; D005786:Gene Expression Regulation; D006107:Granulosa Cells / Q000378:metabolism; D008183:Luteal Phase / Q000235:genetics; D007986:Luteinizing Hormone / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000378:metabolism; D010060:Ovulation / Q000235:genetics; D011388:Prolactin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D013799:Theca Cells / Q000378:metabolism; D014158:Transcription, Genetic; D000511:alpha-Macroglobulins / Q000378:metabolism*
D012333:RNA, Messenger; D000511:alpha-Macroglobulins; D011388:Prolactin; D007986:Luteinizing Hormone