Project description:Reconstruction of a Global Transcriptional Regulatory Network for Control of Lipid Metabolism in Yeast by Using Chromatin Immunoprecipitation with Lambda Exonuclease Digestion
Project description:We propose a carbon source dependent genetic regulatory network for the budding yeast Saccharomyces cerevisiae, derived from quantitative proteomic analyses integrated with bioinformatics knowledge of regulatory pathways and protein interactions. The proposed network, comprising 1247 transcription factor interactions and 126 chaperone interactions, defines the proteome shift in the cell when growing under different carbon sources. We used a label-free proteomics strategy to quantify alterations in protein abundance for S. cerevisiae when grown on minimal media using glucose, galactose, maltose and trehalose as sole carbon sources.
Project description:In Saccharomyces cerevisiae, the kinase Rio1 regulates rDNA transcription and segregation, pre-rRNA cleavage, and 40S ribosomal subunit maturation. Other roles are unknown. Human orthologue RIOK1; which is frequently overexpressed in malignancies, drives tumor growth and metastasis. Again, also RIOK1 biology is poorly understood. In this study, we charted the global activity of Rio1 in budding yeast. By producing and systems-integrating its protein-interaction, gene-transcription, and chromatin-binding maps we generated Rio1's multi-layered activity network, which controls protein synthesis and turnover, metabolism, growth, proliferation, and genetic stability. Rio1 regulates itself at the transcriptional level, and manages its network both directly and indirectly, via a battery of regulators and transcription factors, including Gcn4. We experimentally confirmed the network and show that Rio1 commands its downstream circuit depending on the growth conditions encountered. We also find that Rio1 and RIOK1 activities are functionally equivalent. Our data suggest that pathological RIOK1 expression may deregulate its network and fuel promiscuous transcription and ribosome production, uncontrolled metabolism, growth, proliferation, and chromosomal instability; well-known contributors to cancer initiation, maintenance and metastasis.
Project description:A network governing DNA integrity was identified in yeast by a global genetic analysis of synthetic fitness or lethality defect (SFL) interactions. Within this network, multiple functional modules or mini-pathways were defined according to their common patterns of global SFL interactions and available protein-protein interaction information. Modules or genes involved in DNA replication, DNA replication checkpoint signaling, and oxidative stress response were identified as the major guardians against lethal spontaneous DNA damage, efficient repair of which requires the functions of the DNA damage checkpoint signaling and multiple DNA repair pathways. This genome-wide genetic interaction network also revealed potential roles of a number of genes and modules in mitotic DNA replication and maintenance of genomic stability. These include DIA2, NPT1, HST3, HST4, and the CSM1/LRS4 module (CSM1m). Likewise, the CTF18 module (CTF18m), previously implicated in sister chromatid cohesion, was found to participate in the DNA replication checkpoint. Keywords: dose response
Project description:Splicing regulatory networks are essential components of eukaryotic gene expression programs, yet little is known about how they are integrated with transcriptional regulatory networks into coherent gene expression programs. Here we define the MER1 splicing regulatory network and examine its role in the gene expression program during meiosis in budding yeast. Mer1p splicing factor promotes splicing of just four pre-mRNAs. All four Mer1p-responsive genes also require Nam8p for splicing activation by Mer1p, however other genes require Nam8p but not Mer1p, exposing an overlapping meiotic splicing network controlled by Nam8p. MER1 mRNA and three of the four Mer1p substrate pre-mRNAs are induced by the transcriptional regulator Ume6p. This unusual arrangement delays expression of Mer1p-responsive genes relative to other genes under Ume6p control. Products of Mer1p-responsive genes are required for initiating and completing recombination, and for activation of Ndt80p, the transcriptional network that controls subsequent steps in the program. Thus the MER1 splicing regulatory network mediates the dependent relationship between the UME6 and NDT80 transcriptional regulatory networks in the meiotic gene expression program. This work reveals how splicing regulatory networks can be interlaced with transcriptional regulatory networks in eukaryotic gene expression programs. This SuperSeries is composed of the SubSeries listed below.