Project description:Comparative genomic hybridization was performed to compare amplification gradients of stage 13 follicle cells from several DNA damage checkpoint and double-strand break repair mutants to wild-type (OrR) gradients. Two-three replicates were done for each genotype.
Project description:All cells and organisms exhibit stress-coping mechanisms to ensure survival. Cytoplasmic protein-RNA assemblies termed stress granules are increasingly recognized to promote cellular survival under stress. Thus, they might represent tumor vulnerabilities that are currently poorly explored. The translation-inhibitory eIF2α kinases are established as main drivers of stress granule assembly. Using a systems approach, we identify the translation enhancers PI3K and MAPK/p38 as pro-stress-granule-kinases. They act through the metabolic master regulator mammalian target of rapamycin complex 1 (mTORC1) to promote stress granule assembly. When highly active, PI3K is the main driver of stress granules; however, the impact of p38 becomes apparent as PI3K activity declines. PI3K and p38 thus act in a hierarchical manner to drive mTORC1 activity and stress granule assembly. Of note, this signaling hierarchy is also present in human breast cancer tissue. Importantly, only the recognition of the PI3K-p38 hierarchy under stress enabled the discovery of p38’s role in stress granule formation. In summary, we assign a new pro-survival function to the key oncogenic kinases PI3K and p38, as they hierarchically promote stress granule formation.
Project description:CGH of stage 13 amplifying follicle cells to measure changes in replication fork progression in double-strand break repair mutants Comparative genomic hybridization was performed to compare amplification gradients of stage 13 follicle cells from several double-strand break repair mutants to wild type (OrR) gradients. Two-three replicates were done for each genotype.
Project description:All cells and organisms exhibit stress-coping mechanisms toensure survival. Cytoplasmic protein-RNA assemblies termedstress granules are increasingly recognized to promote cellularsurvival under stress. Thus, they might represent tumor vul-nerabilities that are currently poorly explored. The translation-inhibitory eIF2αkinases are established as main drivers ofstress granule assembly. Using a systems approach, we identifythe translation enhancers PI3K and MAPK/p38 as pro-stress-granule-kinases. They act through the metabolic master regu-lator mammalian target of rapamycin complex 1 (mTORC1) topromote stress granule assembly. When highly active, PI3K is themain driver of stress granules; however, the impact of p38becomes apparent as PI3K activity declines. PI3K and p38 thusact in a hierarchical manner to drive mTORC1 activity and stressgranule assembly. Of note, this signaling hierarchy is also presentin human breast cancer tissue. Importantly, only the recognition ofthe PI3K-p38 hierarchy under stress enabled the discovery of p38’srole in stress granule formation. In summary, we assign a new pro-survival function to the key oncogenic kinases PI3K and p38, as theyhierarchically promote stress granule formation
Project description:Comparative genomic hybridization was performed to compare amplificaiton gradients in genomic DNA derived from stage 13 egg chambers of wild-type, suppressor of under-replication (SuUR) mutant and SuUR overexpression, compared with 0-2hr diploid embryo gDNA. Comparative genomic hybridization was performed to compare amplificaiton gradients in genomic DNA derived from stage 10B egg chambers of wild-type, compared with 0-2hr diploid embryo gDNA.
Project description:Small RNAs recently emerged as a new class of mobile instructive signals in development. Here, we investigate their mechanism of action and show that the gradients formed by mobile small RNAs generate sharply defined domains of target gene expression. By modulating the source of artificial miRNAs we show that boundary formation is an inherent property of the small RNA gradient itself. The threshold-based readout of such gradients is highly sensitive to small RNA levels at the source, allowing plasticity in the positioning of a target gene expression boundary. In addition to generating sharp expression domains of their immediate targets, the readouts of opposing small RNA gradients enable formation of stable and uniformly positioned developmental boundaries. These novel patterning properties of small RNAs are reminiscent of those of morphogens in animal systems. However, their exceptionally high specificity, direct mode of action, and the fully intrinsic nature of their gradients, distinguish mobile small RNAs from classical morphogens. Our findings present mobile small RNAs and their targets as highly portable and evolutionarily-tractable regulatory modules through which to create pattern in development and beyond.