The activity of the DAF-2 insulin-like receptor is required for Caenorhabditis elegans reproductive growth and normal adult life span. Informatic analysis identified 37 C. elegans genes predicted to encode insulin-like peptides. Many of these genes are divergent insulin superfamily members, and many are clustered, indicating recent diversification of the family. The ins genes are primarily expressed in neurons, including sensory neurons, a subset of which are required for reproductive development. Structural predictions and likely C-peptide cleavage sites typical of mammalian insulins suggest that ins-1 is most closely related to insulin. Overexpression of ins-1, or expression of human insulin under the control of ins-1 regulatory sequences, causes partially penetrant arrest at the dauer stage and enhances dauer arrest in weak daf-2 mutants, suggesting that INS-1 and human insulin antagonize DAF-2 insulin-like signaling. A deletion of the ins-1 coding region does not enhance or suppress dauer arrest, indicating a functional redundancy among the 37 ins genes. Of five other ins genes tested, the only other one bearing a predicted C peptide also antagonizes daf-2 signaling, whereas four ins genes without a C peptide do not, indicating functional diversity within the ins family. Insulin and its related proteins define a superfamily of secreted proteins that share a structural motif stabilized by a set of stereotypical disulfide bonds (Blundell and Humbel 1980;Murray-Rust et al. 1992). Insulin superfamily genes are ubiquitous in vertebrates, and have been identified in invertebrates, including insects, molluscs, and the nematode Caenorhabditis elegans (Duret et al. 1998;Gregoire et al. 1998;Smit et al. 1998;Kawano et al. 2000). Seven members of the insulin superfamily have been identified in humans, including insulin (Brown et al. 1955), insulin-like growth factors (IGFs) I and II (Rinderknecht and Humbel 1978a,b), relaxins HI and HII (Bedarkar et al. 1977;Schwabe and McDonald 1977), early placenta insulin-like peptide (EPIL) (Chassin et al. 1995;Koman et al. 1996), and relaxin-like factor (Bullesbach and Schwabe 1995). These hormones mediate diverse functions. Insulin is a metabolic hormone that acts on target tissues to increase glucose uptake and energy storage, IGFs are mitogenic stimulators that control cell survival and proliferation, and relaxin causes dilation of the symphysis pubis before parturition and vasodilation. No function is yet known for either EPIL or relaxin-like factor. Bombyxin in silk moths (Satake et al. 1997), and the neurons that secrete locust and molluscan insulin-related proteins (Smit et al. 1988;Lagueux et al. 1990) regulate metabolism, implicating insulin-like proteins in metabolic control broadly in animal phylogeny. The insulin-like proteins that regulate metabolism, insulin in vertebrates, bombyxin from silk moths, molluscan MIP, and locust LIRP, appear to be processed proteolytically to remove an internal C peptide (Smit et al. 1988;Lagueux et al. 1990;Kondo et al. 1996). This proc...
BackgroundThe investigation of the interconnections between the molecular and genetic events that govern biological systems is essential if we are to understand the development of disease and design effective novel treatments. Microarray and next-generation sequencing technologies have the potential to provide this information. However, taking full advantage of these approaches requires that biological connections be made across large quantities of highly heterogeneous genomic datasets. Leveraging the increasingly huge quantities of genomic data in the public domain is fast becoming one of the key challenges in the research community today.Methodology/ResultsWe have developed a novel data mining framework that enables researchers to use this growing collection of public high-throughput data to investigate any set of genes or proteins. The connectivity between molecular states across thousands of heterogeneous datasets from microarrays and other genomic platforms is determined through a combination of rank-based enrichment statistics, meta-analyses, and biomedical ontologies. We address data quality concerns through dataset replication and meta-analysis and ensure that the majority of the findings are derived using multiple lines of evidence. As an example of our strategy and the utility of this framework, we apply our data mining approach to explore the biology of brown fat within the context of the thousands of publicly available gene expression datasets.ConclusionsOur work presents a practical strategy for organizing, mining, and correlating global collections of large-scale genomic data to explore normal and disease biology. Using a hypothesis-free approach, we demonstrate how a data-driven analysis across very large collections of genomic data can reveal novel discoveries and evidence to support existing hypothesis.
A screen for modifiers of Dpp adult phenotypes led to the identification of the Drosophila homolog of the Sno oncogene (dSno). The dSno locus is large, transcriptionally complex and contains a recent retrotransposon insertion that may be essential for dSno function, an intriguing possibility from the perspective of developmental evolution. dSno is highly transcribed in the embryonic central nervous system and transcripts are most abundant in third instar larvae. dSno mutant larvae have proliferation defects in the optic lobe of the brain very similar to those seen in baboon (Activin type I receptor) and dSmad2 mutants. This suggests that dSno is a mediator of Baboon signaling. dSno binds to Medea and Medea/dSno complexes have enhanced affinity for dSmad2. Alternatively, Medea/dSno complexes have reduced affinity for Mad such that, in the presence of dSno, Dpp signaling is antagonized. We propose that dSno functions as a switch in optic lobe development, shunting Medea from the Dpp pathway to the Activin pathway to ensure proper proliferation. Pathway switching in target cells is a previously unreported mechanism for regulating TGFb signaling and a novel function for Sno/Ski family proteins.
PurposeTo develop a comprehensive genetic test for female and male infertility in support of medical decisions during assisted reproductive technology (ART) protocols.MethodsWe developed a next-generation sequencing (NGS) gene panel consisting of 87 genes including promoters, 5′ and 3′ untranslated regions, exons, and selected introns. In addition, sex chromosome aneuploidies and Y chromosome microdeletions were analyzed concomitantly using the same panel.ResultsThe NGS panel was analytically validated by retrospective analysis of 118 genomic DNA samples with known variants in loci representative of female and male infertility. Our results showed analytical accuracy of > 99%, with > 98% sensitivity for single-nucleotide variants (SNVs) and > 91% sensitivity for insertions/deletions (indels). Clinical sensitivity was assessed with samples containing variants representative of male and female infertility, and it was 100% for SNVs/indels, CFTR IVS8-5T variants, sex chromosome aneuploidies, and copy number variants (CNVs) and > 93% for Y chromosome microdeletions. Cost analysis shows potential savings when comparing this single NGS assay with the standard approach, which includes multiple assays.ConclusionsA single, comprehensive, NGS panel can simplify the ordering process for healthcare providers, reduce turnaround time, and lower the overall cost of testing for genetic assessment of infertility in females and males, while maintaining accuracy.Electronic supplementary materialThe online version of this article (10.1007/s10815-018-1204-7) contains supplementary material, which is available to authorized users.
TGFb and Wnt pathways play important roles in the development of animals from sponges to humans. In both pathways posttranslational modification as a means of regulating their function, such as lysine modification by ubiquitination and sumoylation, has been observed. However, a gap exists between the immunological observation of posttranslational modification and the identification of the target lysine. To fill this gap, we conducted a phylogenetic analysis of lysine conservation and context in TGFb and Wnt pathway receptors and signal transducers and suggest numerous high-probability candidates for posttranslational modification. Further comparison of results from both pathways suggests two general features for biochemical regulation of intercellular signaling: receptors are less frequent targets for modification than signal transduction agonists, and a lysine adjacent to an upstream hydrophobic residue may be a preferred context for modification. Overall the results suggest numerous applications for an evolutionary approach to the biochemical regulation of developmental pathways, including (1) streamlining of the identification of the target lysine, (2) determination of when members of a multigene family acquire distinct activities, (3) application to any conserved protein family, and (4) application to any modification of a specific amino acid.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.