Project description:We previously demonstrated that the NF-κB inhibitor IκBα binds the chromatin together with PRC2 to regulate a subset of developmental- and stem cell-related genes. This alternative function has been elusive in both physiological and disease conditions because of the predominant role of IκBα as a negative regulator of NF-κB. We here uniquely characterize specific residues of IκBα that allow the generation of separation-of-function (SOF) mutants that are defective for either NF-κBrelated (SOF DeltaNF-κB) or chromatin-related (SOF DeltaH2A,H4) activities. Expression of IκBα SOF DeltaNF-κB, but not SOF DeltaH2A/H4, is sufficient to negatively regulate a specific stemness program in intestinal cells, thus rescuing the differentiation blockage imposed by IκBα deficiency. . By ChIP assay we demonstrated IκBα binding to several stem cell genes that are transcriptionally repressed following IκBα SOF DeltaNF-κB induction. Our data indicate that SOF mutants represent an exclusive tool for studying IκBα functions in physiology and disease.
Project description:We previously demonstrated that the NF-κB inhibitor IκBα binds the chromatin together with PRC2 to regulate a subset of developmental- and stem cell-related genes. This alternative function has been elusive in both physiological and disease conditions because of the predominant role of IκBα as a negative regulator of NF-κB. We here uniquely characterize specific residues of IκBα that allow the generation of separation-of-function (SOF) mutants that are defective for either NF-κBrelated (SOF DeltaNF-κB) or chromatin-related (SOF DeltaH2A,H4) activities. Expression of IκBα SOF DeltaNF-κB, but not SOF DeltaH2A/H4, is sufficient to negatively regulate a specific stemness program in intestinal cells, thus rescuing the differentiation blockage imposed by IκBα deficiency. . By ChIP assay we demonstrated IκBα binding to several stem cell genes that are transcriptionally repressed following IκBα SOF DeltaNF-κB induction. Our data indicate that SOF mutants represent an exclusive tool for studying IκBα functions in physiology and disease.
Project description:We previously demonstrated that the NF-κB inhibitor IκBα binds the chromatin together with PRC2 to regulate a subset of developmental- and stem cell-related genes. This alternative function has been elusive in both physiological and disease conditions because of the predominant role of IκBα as a negative regulator of NF-κB. We here uniquely characterize specific residues of IκBα that allow the generation of separation-of-function (SOF) mutants that are defective for either NF-κBrelated (SOF DeltaNF-κB) or chromatin-related (SOF DeltaH2A,H4) activities. Expression of IκBα SOF DeltaNF-κB, but not SOF DeltaH2A/H4, is sufficient to negatively regulate a specific stemness program in intestinal cells, thus rescuing the differentiation blockage imposed by IκBα deficiency. . By ChIP assay we demonstrated IκBα binding to several stem cell genes that are transcriptionally repressed following IκBα SOF DeltaNF-κB induction. Our data indicate that SOF mutants represent an exclusive tool for studying IκBα functions in physiology and disease.
Project description:The project aims to use photocycle mutants to understand the importance of phot2 autophosphorylation for signaling leading to chloroplast accumulation and avoidance. The second part is focused on the identification of new interacting proteins for phot2.
Characterization of proteins important for signaling leading to chloroplast avoidance. PHOT2-GFP wild type and PHOT2-V392L-GFP muteins were immunoprecipitated from leaves of transgenic Arabidopsis plants, either dark-adapted or irradiated with low or high blue light. Proteins identified by Mass Spectrometry as interacting with wild-type PHOT2-GFP and PHOT2-V392L-GFP were compared to identify proteins putatively involved in chloroplast avoidance. Phosphorylation profiles of PHOT2-GFP wild type and PHOT2-V392L-GFP were analyzed to distinguish between phosphorylation sites characteristic for chloroplast accumulation and avoidance.
