Showing papers by "Michael G. Rosenfeld published in 1981"
TL;DR: It is reported here that the conversion from a ’high’ to a ‘low’ calcitonin producing state is associated with specific modifications of the calcitonIn mRNA synthetic pathway and a consequence of these changes seems to be the production of a new cytoplasmic mRNA.
Abstract: The selective control of gene expression results in diversified morphology and physiological function. Understanding the expression of differentiated function in molecular terms requires detailed characterization of the regulation of mRNA synthesis and catabolism. Although considerable emphasis has been placed on transcriptional control, the discovery of HnRNA and 'split genes' gives rise to the possibility of post-transcriptional regulation at the level of processing of nuclear precursors. A rat calcitonin-producing medullary thyroid carcinoma (MTC) line was used as a model for definition of certain aspects in regulation of gene expression. Serial transplantation of several rat MTC lines containing and secreting large amounts of calcitonin generated tumours in which calcitonin biosynthesis was decreased more than 10-fold. We report here that the conversion from a 'high' to a 'low' calcitonin producing state is associated with specific modifications of the calcitonin mRNA synthetic pathway and a consequence of these changes seems to be the production of a new cytoplasmic mRNA.
91 citations
TL;DR: This report directly documents that a polypeptide hormone can regulate specific gene expression as a consequence of increasing the levels of a primary genomic transcript.
Abstract: This report directly documents that a polypeptide hormone can regulate specific gene expression as a consequence of increasing the levels of a primary genomic transcript. The regulation and expression of the prolactin gene was studied in a cell line (GH4) derived from a rat pituitary tumor. These cells respond to addition of the hypothalamic tripeptide, thyrotropin-releasing hormone (TRH; thyroliberin), by elevation of the levels of mature prolactin mRNA and increase in prolactin biosynthesis. The message induction is preceded by, and apparently consequential to, a comparable rapid increase in the nuclear prolactin RNA precursors, including the putative primary transcript.
77 citations