Project description:The evolutionarily conserved Wnt/?-catenin signaling pathway plays a fundamental role during metazoan development, regulating numerous processes including cell fate specification, cell migration, and stem cell renewal. Wnt ligand binding leads to stabilization of the transcriptional effector ?-catenin and upregulation of target gene expression to mediate a cellular response. During larval development of the nematode Caenorhabditis elegans, Wnt/?-catenin pathways act in fate specification of two hypodermal cell types, the ventral vulval precursor cells (VPCs) and the lateral seam cells. Because little is known about targets of the Wnt signaling pathways acting during larval VPC and seam cell differentiation, we sought to identify genes regulated by Wnt signaling in these two hypodermal cell types. We conditionally activated Wnt signaling in larval animals and performed cell type?specific "mRNA tagging" to enrich for VPC and seam cell?specific mRNAs, and then used microarray analysis to examine gene expression compared to control animals. Two hundred thirty-nine genes activated in response to Wnt signaling were identified, and we characterized 50 genes further. The majority of these genes are expressed in seam and/or vulval lineages during normal development, and reduction of function for nine genes caused defects in the proper division, fate specification, fate execution, or differentiation of seam cells and vulval cells. Therefore, the combination of these techniques was successful at identifying potential cell type?specific Wnt pathway target genes from a small number of cells and at increasing our knowledge of the specification and behavior of these C. elegans larval hypodermal cells.
Project description:The nematode Caenorhabditis elegans has evolutionarily conserved EV signaling pathways. In this study, we apply a recently published method for high specificity purification of EVs from C. elegans to carry out target-independent proteomic and RNA analysis of EVs from C. elegans. Our experiments uncovered diverse coding and non-coding RNA transcripts as well as protein cargo types commonly found in human EVs.
Project description:Inhibition of insulin/IGF-1 signaling (IIS) represents a promising avenue for the treatment of mitochondrial diseases, although many of the molecular mechanisms underlying this beneficial effect remain elusive. Here, we investigate the phosphoproteomic landscape of Caenorhabditis elegans with severe mitochondrial deficiency in the context of insulin signaling inhibition.
Project description:Inhibition of insulin/IGF-1 signaling (IIS) represents a promising avenue for the treatment of mitochondrial diseases, although many of the molecular mechanisms underlying this beneficial effect remain elusive. Here, we investigate the proteomic landscape of Caenorhabditis elegans with severe mitochondrial deficiency in the context of insulin signaling inhibition.
Project description:The roundworm Caenorhabditis elegans is a heme auxotroph that requires the coordinated actions of HRG-1 heme permeases to transport environmental heme into the intestine and HRG-3, a secreted protein, to deliver intestinal heme to other tissues including the embryo. Here we show that heme homeostasis in the extraintestinal hypodermal tissue is facilitated by the transmembrane protein HRG-2. Systemic heme deficiency upregulates hrg-2 mRNA expression over 200-fold in the main body hypodermal syncytium hyp 7. HRG-2 is a type I membrane protein which binds heme and localizes to the endoplasmic reticulum and apical plasma membrane. Cytochrome heme profiles are aberrant in HRG-2 deficient worms, a phenotype that is partially suppressed by heme supplementation. Heme-deficient yeast strain, ectopically expressing worm HRG-2, reveal significantly improved growth at submicromolar concentrations of exogenous heme. Taken together, our results implicate HRG-2 as a facilitator of heme utilization in the C. elegans hypodermis and provide a mechanism for regulation of heme homeostasis in an extraintestinal tissue. Two experimental groups: Group 1: three 4um Controls vs. three 4uM hrg-2 Mutants; Group 2: three 20um Controls vs. three 20uM hrg-2 Mutants
Project description:The roundworm Caenorhabditis elegans is a heme auxotroph that requires the coordinated actions of HRG-1 heme permeases to transport environmental heme into the intestine and HRG-3, a secreted protein, to deliver intestinal heme to other tissues including the embryo. Here we show that heme homeostasis in the extraintestinal hypodermal tissue is facilitated by the transmembrane protein HRG-2. Systemic heme deficiency upregulates hrg-2 mRNA expression over 200-fold in the main body hypodermal syncytium hyp 7. HRG-2 is a type I membrane protein which binds heme and localizes to the endoplasmic reticulum and apical plasma membrane. Cytochrome heme profiles are aberrant in HRG-2 deficient worms, a phenotype that is partially suppressed by heme supplementation. Heme-deficient yeast strain, ectopically expressing worm HRG-2, reveal significantly improved growth at submicromolar concentrations of exogenous heme. Taken together, our results implicate HRG-2 as a facilitator of heme utilization in the C. elegans hypodermis and provide a mechanism for regulation of heme homeostasis in an extraintestinal tissue.