Heat stress transcription factor HsfA5 as specific repressor of HsfA4 [Elektronische Ressource] / von Sanjeev Kumar Baniwal

Heat stress transcription factor HsfA5 as specific repressor of HsfA4 Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften von Sanjeev Kumar Baniwal aus Neu Delhi, Indien vorgelegt beim Fachbereich Biowissenschaften der Johann Wolfgang Goethe-Universität Frankfurt am Main, Januar, 2007 Table of contents Table of contents 1 Introduction 1.1 Heat stress response and Hsf proteins 1 1.2 All Hsfs possess highly conserved functional modules 2 1.3 Regulation of Hsf transcriptional activity 3 1.3.1 Post translational modifications 3 1.3.2 Ribonucleoprotein complex 4 1.3.3 Molecular chaperones 4 1.4 Heat shock factor binding protein (HSBP) 5 1.5 Characteristic features of heat stress transcription factor proteins in plants 7 1.6 Multiplicity of plant Hsfs: Redundancy versus diversification of unction 8 1.6.1 HsfA1a as master regulator of thermotolerance in tomato 8 1.6.2 HsfB1 as co-regulator of heat stress as well as house-keeping genes 10 1.6.3 HsfA2 is exclusively expressed under hs-conditions and has a dominant role 11 1.6.4 HsfA9 is exclusively expressed during late stages of seed development 13 1.6.5 HsfA4 as anti-apoptotic factor and regulator ofredox-regulated gene expression 14 1.7 Objectives of the thesis 15 2 Materials and methods 2.1 General reagents and procedures 16 2.