UDP-glucose 4-epimerase regulation
Abstract
The relative roles of transcriptional and post-translational control of UDP-glucose 4-epimerase in plant cell wall biosynthesis Georg J. Seifert FWF proposal The staggering structural and developmental complexity of the plant cell wall is matched by an equally complex armoury of genes acting in cell wall carbohydrate biosynthesis and remodelling. Plants possess sophisticated sugar biosynthetic machinery comprising isoforms of nucleotide sugar interconversion enzymes (NSEs) encoded by small gene families – a unique and unexplained feature of plant genomes. The central hypothesis of this proposal states that the control of NSE isoforms regulates glycosylation patterns in response to developmental, metabolic and stress-related cues, thereby linking signalling networks with primary metabolism and the dynamics of the cell wall. Specialized roles for individual NSE isoforms have been proposed, based on genetic evidence and supported by enzyme kinetic and molecular biological studies and cytological observations. Presently the mechanistic basis of carbohydrate biosynthesis control at the level of nucleotide sugar metabolism is largely elusive, control might be exerted both at the level of transcription and at a post-transcriptional or post-translational level. UDP-D-glucose 4-epimerase (UGE), which interconverts UDP-glucose and UDP-galactose, is required for the biosynthesis of a wide variety of biologically and economically important carbohydrates in plants. The family of five Arabidopsis thaliana UGE genes represents the well-characterized paradigm for NSE specialization. Here it is proposed to investigate the mechanistic basis of genetic isoform specialization of plant UGEs and their roles in nucleotide sugar flux control and carbohydrate biosynthesis by directly assessing the contribution of transcriptional vs. post-transcriptional regulation and to establish the significance of protein phosphorylation for isoform function. In a wider context this work will shed light on the regulation of cell wall carbohydrate biosynthesis – a field of increasing importance for human society.
Publikationen
Project staff
Georg Seifert
Priv.-Doz. Dipl.-Ing. Dr.rer.nat. Georg Seifert
georg.seifert@boku.ac.at
Tel: +43 1 47654-94044, 94054
Project Leader
01.10.2009 - 30.09.2014