@phdthesis{Sin2016, author = {Sin, Celine}, title = {Post-transcriptional control of gene expression}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102469}, school = {Universit{\"a}t Potsdam}, pages = {xxv, 238}, year = {2016}, abstract = {Gene expression describes the process of making functional gene products (e.g. proteins or special RNAs) from instructions encoded in the genetic information (e.g. DNA). This process is heavily regulated, allowing cells to produce the appropriate gene products necessary for cell survival, adapting production as necessary for different cell environments. Gene expression is subject to regulation at several levels, including transcription, mRNA degradation, translation and protein degradation. When intact, this system maintains cell homeostasis, keeping the cell alive and adaptable to different environments. Malfunction in the system can result in disease states and cell death. In this dissertation, we explore several aspects of gene expression control by analyzing data from biological experiments. Most of the work following uses a common mathematical model framework based on Markov chain models to test hypotheses, predict system dynamics or elucidate network topology. Our work lies in the intersection between mathematics and biology and showcases the power of statistical data analysis and math modeling for validation and discovery of biological phenomena.}, language = {en} } @misc{PueschelChrist1994, author = {P{\"u}schel, Gerhard Paul and Christ, Bruno}, title = {Inhibition by PGE₂ of glucagon-induced increase in phosphoenolpyruvate carboxykinase mRNA and acceleration of mRNA degradation in cultured rat hepatocytes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45792}, year = {1994}, abstract = {In cultured rat hepatocytes the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK) is known to be induced by glucagon via an elevation of cAMP. Prostaglandin E₂ has been shown to antagonize the glucagon-activated cAMP formation, glycogen phosphorylase activity and glucose output in hepatocytes. It was the purpose of the current investigation to study the potential of PGE₂ to inhibit the glucagon-induced expression of PCK on the level of mRNA and enzyme activity. PCK mRNA and enzyme activity were increased by 0.1 nM glucagon to a maximum after 2 h and 4 h, respectively. This increase was completely inhibited if 10 μM PGE2 was added concomitantly with glucagon. This inhibition by PGE₂ of glucagon-induced PCK activity was abolished by pertussis toxin treatment. When added at the maximum of PCK mRNA at 2 h, PGE₂ accelerated the decay of mRNA and reduced enzyme activity. This effect was not reversed by pertussis toxin treatment. Since in liver PGE₂ is derived from Kupffer cells, which play a key role in the local inflammatory response, the present data imply that during inflammation PGE₂ may reduce the hepatic gluconeogenic capacity via a Gᵢ-linked signal chain.}, language = {en} }