Identification of bioactive compounds in diabetes and infertility models of C. elegans

Polycystic ovary syndrome (POS) is a complex and heterogeneous endocrine disease characterized by hyperandrogenism, oligo-anovulation and metabolic disorders, including insulin resistance, obesity and type II diabetes. Additionally, POS causes infertility in childbearing age women, making of great interest the search of new treatments and compounds for the improvement of the symptoms of this chronic disease. Despite the definitive pathological mechanism of POS is still unknown, as mentioned before there is a strong relation between the syndrome and different alterations in the insulin signaling pathway. This pathway is evolutionary conserved and it has a homologue pathway in the organism Caenorhabditis elegans. Mutations in the insulin receptor homologue daf-2 gene or in the phosphatidylinositol 3-kinase (PI3K) homologue age-1, result in reduction of fertility, being the decrease in progeny sharper in the allele age-1(mg305) mutant, in addition to a less pleiotropic effect. We consider this mutant of C. elegans a good model to study the insulin pathway, and specifically POS, due to the high degree of conservation of the pathway and the similarities between the phenotype caused by the mutation and the human symptoms

Pkc-1 conecta dos rutas de control endocrino en C. elegans para regular desarrollo y longevidad

Resumen del trabajo presentado al XXXVII Congreso de la Sociedad Española de Genética, celebrado en Torremolinos (Málaga) del 29 de septiembre al 2 de octubre de 2009.En C. elegans, daf-2, homologo del receptor de la ruta insulina/IGF, regula negativamente tanto la formación de un estadio de resistencia llamado dauer y como la longevidad. Así mutantes en este gen son propensos a entrar en dauer y a su vez son longevos durante su fase adulta. Buscando mutantes que suprimieran ambos fenotipos hemos encontrado una pérdida de función en el gen pkc-1, una proteina quinasa C. Estudiando este mutante en pkc-1 hemos descubierto que se comporta de forma similar a otro gen, previamente descrito como supresor de mutantes en la ruta de la insulina/IGF, el receptor de hormonas nucleares daf-12. Por otro lado nuestros resultados sugieren que su comportamiento es diferente al factor de transcripción daf-16, conocido por ser el factor principal controlado por la ruta de la Insulina/IGF. En este trabajo demostramos que pkc-1 es un punto de conexión, hasta ahora no descrito, entre la ruta de la insulina y la ruta de la hormona nuclear daf-12, tanto en el control de la formación de dauer como en el de longevidad.Peer reviewe

Using AnABlast for intergenic sORF prediction in the Caenorhabditis elegans genome.

Short bioactive peptides encoded by small open reading frames (sORFs) play important roles in eukaryotes. Bioinformatics prediction of ORFs is an early step in a genome sequence analysis, but sORFs encoding short peptides, often using non-AUG initiation codons, are not easily discriminated from false ORFs occurring by chance. AnABlast is a computational tool designed to highlight putative protein-coding regions in genomic DNA sequences. This protein-coding finder is independent of ORF length and reading frame shifts, thus making of AnABlast a potentially useful tool to predict sORFs. Using this algorithm, here, we report the identification of 82 putative new intergenic sORFs in the Caenorhabditis elegans genome. Sequence similarity, motif presence, expression data and RNA interference experiments support that the underlined sORFs likely encode functional peptides, encouraging the use of AnABlast as a new approach for the accurate prediction of intergenic sORFs in annotated eukaryotic genomes. AnABlast is freely available at http://www.bioinfocabd.upo.es/ab/. The C.elegans genome browser with AnABlast results, annotated genes and all data used in this study is available at http://www.bioinfocabd.upo.es/celegans. Supplementary data are available at Bioinformatics online

pkc-1 regulates daf-2 insulin/IGF signalling-dependent control of dauer formation in Caenorhabditis elegans

In Caenorhabditis elegans, the insulin/IGF pathway participates in the decision to initiate dauer development. Dauer is a diapause stage that is triggered by environmental stresses, such as a lack of nutrients. Insulin/IGF receptor mutants arrest constitutively in dauer, an effect that can be suppressed by mutations in other elements of the insulin/IGF pathway or by a reduction in the activity of the nuclear hormone receptor daf-12. We have isolated a pkc-1 mutant that acts as a novel suppressor of the dauer phenotypes caused by insulin/IGF receptor mutations. Interactions between insulin/IGF mutants and the pkc-1 suppressor mutant are similar to those described for daf-12 or the DAF-12 coregulator din-1. Moreover, we show that the expression of the DAF-12 target daf-9, which is normally elevated upon a reduction in insulin/IGF receptor activity, is suppressed in a pkc-1 mutant background, suggesting that pkc-1 could link the daf-12 and insulin/IGF pathways. pkc-1 has been implicated in the regulation of peptide neurosecretion in C. elegans. Although we demonstrate that pkc-1 expression in the nervous system regulates dauer formation, our results suggest that the requirement for pkc-1 in neurosecretion is independent of its role in modulating insulin/IGF signalling. pkc-1 belongs to the novel protein kinase C (nPKC) family, members of which have been implicated in insulin resistance and diabetes in mammals, suggesting a conserved role for pkc-1 in the regulation of the insulin/IGF pathway.This work was supported by the Spanish Ministry of Science (MICINN) BFU2006-07391 ⁄ BMC, the European Regional Development Fund (FEDER) and the Junta de Andalucía Project P07-CVI-02697. JMM was supported by the FPU program of the Spanish Ministry of Science. AMB was supported by a Plan Propio de Investigación fellowship from UPO. MMP was supported by a Junta de Andalucía fellowship.Peer Reviewe

Cytoplasmic LSM-1 protein regulates stress responses through the insulin/IGF-1 signaling pathway in Caenorhabditis elegans.

Genes coding for members of the Sm-like (LSm) protein family are conserved through evolution from prokaryotes to humans. These proteins have been described as forming homo- or heterocomplexes implicated in a broad range of RNA-related functions. To date, the nuclear LSm2-8 and the cytoplasmic LSm1-7 heteroheptamers are the best characterized complexes in eukaryotes. Through a comprehensive functional study of the LSm family members, we found that lsm-1 and lsm-3 are not essential for C. elegans viability, but their perturbation, by RNAi or mutations, produces defects in development, reproduction, and motility. We further investigated the function of lsm-1, which encodes the distinctive protein of the cytoplasmic complex. RNA-seq analysis of lsm-1 mutants suggests that they have impaired Insulin/IGF-1 signaling (IIS), which is conserved in metazoans and involved in the response to various types of stress through the action of the FOXO transcription factor DAF-16. Further analysis using a DAF-16::GFP reporter indicated that heat stress-induced translocation of DAF-16 to the nuclei is dependent on lsm-1. Consistent with this, we observed that lsm-1 mutants display heightened sensitivity to thermal stress and starvation, while overexpression of lsm-1 has the opposite effect. We also observed that under stress, cytoplasmic LSm proteins aggregate into granules in an LSM-1-dependent manner. Moreover, we found that lsm-1 and lsm-3 are required for other processes regulated by the IIS pathway, such as aging and pathogen resistance

How can regulation of steroid hormones sulfation levels improve protein aggregation diseases?

Tabajo presentado en Virtual European Worm Meeting, celebrado en modalidad virtual del 22 al 23 de junio de 2020

Using AnABlast for intergenic sORF prediction in the Caenorhabditis elegans

Short bioactive peptides encoded by small open reading frames (sORFs) play important roles in eukaryotes. Bioinformatics prediction of ORFs is an early step in a genome sequence analysis, but sORFs encoding short peptides, often using non-AUG initiation codons, are not easily discriminated from false ORFs occurring by chance. AnABlast is a computational tool designed to highlight putative protein-coding regions in genomic DNA sequences. This protein-coding finder is independent of ORF length and reading frame shifts, thus making of AnABlast a potentially useful tool to predict sORFs. Using this algorithm, here, we report the identification of 82 putative new intergenic sORFs in the Caenorhabditis elegans genome. Sequence similarity, motif presence, expression data and RNA interference experiments support that the underlined sORFs likely encode functional peptides, encouraging the use of AnABlast as a new approach for the accurate prediction of intergenic sORFs in annotated eukaryotic genomes. AnABlast is freely available at http://www.bioinfocabd.upo.es/ab/. The C.elegans genome browser with AnABlast results, annotated genes and all data used in this study is available at http://www.bioinfocabd.upo.es/celegans. Supplementary data are available at Bioinformatics online