Zur Transkriptions- und Translationskontrolle des Gens für Transitionsprotein
von Özlem Topaloglu
Datum der mündl. Prüfung:2000-05-03
Betreuer:Prof. Dr. Dr. Wolfgang Engel
Gutachter:Prof. Dr. Ulrich Grossbach
EnglischIn the framework of this study, the transcriptional and translational regulation of rat Tnp2 gene were investigated by means of in vitro and in vivo systems. In order to determine the minimal promoter region which could direct the testis- and haploid-stage specific expression of the Tnp2 gene, a region of -74 to +70 was alyzed in transgenic mice. Earlier results revealed that a 565 bp 5"UTR can direct tissue- and ime-specific expression of Tnp2 gene in transgenic mice. The region was shortened to 147 bp and transgenic mice carrying this construct was generated. To investigate the role of 3" UTR in the translational repression of Tnp2 mRNA, Tnp2-SV40 transgenic ice line was generated where the 3"UTR of Tnp2 of gene was replaced by SV40 splicing and polyadenlylation sequences to abolish the translational delay for the Tnp2 RNA. An interesting aspect of spermatogenesis is the translational repression of the haploid-stage specific proteins. In order to investigate the need for translational control and the role of 3"UTR in this process, transgenic mice lacking 3"UTR of the rat Tnp2 gene were generated. The expression of the transgenic Tnp2 protein was analyzed and compared with the endogenous Tnp2 protein expression. An already known mechanism for the translational regulation of sprematid-specific mRNAs is the interaction of RNA-binding proteins with the 3"UTRs of the late translated mRNAs during spermiogenesis. RNA-affinity chromatography was employed to show the specific binding of the cytoplasmic proteins to the in vitro transcribed 3"UTR of rat Tnp2.
Keywords: Tnp2; Transcription; Translation; Promoter; RNA-binding Protein