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Muneesh Tewari

Publications and source records attributed to Muneesh Tewari.

8 recordsLinked to original sources
PubMed2006

The 14-3-3 protein FTT-2 regulates DAF-16 in Caenorhabditis elegans.

The Caenorhabditis elegans daf-2/insulin-like signaling pathway is critical for regulating development, longevity, metabolism and stress resistance. We identified the 14-3-3 protein FTT-2 to be a new regulatory component of this pathway. We found that RNAi knock down of ftt-2 specifically enhanced the daf-2-mediated dauer formation phenotype. Furthermore, ftt-2 knock down caused the nuclear accumulation of DAF-16/FOXO, the forkhead transcription factor that is the major downstream effecter of daf-2/insulin-like signaling, and enhanced the transcriptional activities of DAF-16. In contrast to ftt-2, RNAi knock down of par-5/ftt-1, the only other gene predicted to encode a 14-3-3 protein in C. elegans, did not show any notable effect on dauer formation, DAF-16 localization, or DAF-16 downstream gene transcription, underscoring the functional specification of FTT-2 and PAR-5 despite their high sequence homology. Using co-immunoprecipitation, we revealed that FTT-2 formed a complex with GFP-fused DAF-16 in C. elegans. Our results indicate that FTT-2 binds to DAF-16 in C. elegans and regulates DAF-16 by sequestering it in the cytoplasm. A similar mechanism of regulation of FOXO by 14-3-3zeta has been reported in mammalian cells, highlighting the high degree of conservation of the daf-2/insulin-like signaling pathway.

Animals↗
PubMed2005

Functional genomic analysis of RNA interference in C. elegans.

RNA interference (RNAi) of target genes is triggered by double-stranded RNAs (dsRNAs) processed by conserved nucleases and accessory factors. To identify the genetic components required for RNAi, we performed a genome-wide screen using an engineered RNAi sensor strain of Caenorhabditis elegans. The RNAi screen identified 90 genes. These included Piwi/PAZ proteins, DEAH helicases, RNA binding/processing factors, chromatin-associated factors, DNA recombination proteins, nuclear import/export factors, and 11 known components of the RNAi machinery. We demonstrate that some of these genes are also required for germline and somatic transgene silencing. Moreover, the physical interactions among these potential RNAi factors suggest links to other RNA-dependent gene regulatory pathways.

Amino Acid Motifs↗
PubMed2004

Systematic interactome mapping and genetic perturbation analysis of a C. elegans TGF-beta signaling network.

To initiate a system-level analysis of C. elegans DAF-7/TGF-beta signaling, we combined interactome mapping with single and double genetic perturbations. Yeast two-hybrid (Y2H) screens starting with known DAF-7/TGF-beta pathway components defined a network of 71 interactions among 59 proteins. Coaffinity purification (co-AP) assays in mammalian cells confirmed the overall quality of this network. Systematic perturbations of the network using RNAi, both in wild-type and daf-7/TGF-beta pathway mutant animals, identified nine DAF-7/TGF-beta signaling modifiers, seven of which are conserved in humans. We show that one of these has functional homology to human SNO/SKI oncoproteins and that mutations at the corresponding genetic locus daf-5 confer defects in DAF-7/TGF-beta signaling. Our results reveal substantial molecular complexity in DAF-7/TGF-beta signal transduction. Integrating interactome maps with systematic genetic perturbations may be useful for developing a systems biology approach to this and other signaling modules.

Animals↗
PubMed2004

A map of the interactome network of the metazoan C. elegans.

To initiate studies on how protein-protein interaction (or "interactome") networks relate to multicellular functions, we have mapped a large fraction of the Caenorhabditis elegans interactome network. Starting with a subset of metazoan-specific proteins, more than 4000 interactions were identified from high-throughput, yeast two-hybrid (HT=Y2H) screens. Independent coaffinity purification assays experimentally validated the overall quality of this Y2H data set. Together with already described Y2H interactions and interologs predicted in silico, the current version of the Worm Interactome (WI5) map contains approximately 5500 interactions. Topological and biological features of this interactome network, as well as its integration with phenome and transcriptome data sets, lead to numerous biological hypotheses.

Animals↗
PubMed2003

Development of human protein reference database as an initial platform for approaching systems biology in humans.

Human Protein Reference Database (HPRD) is an object database that integrates a wealth of information relevant to the function of human proteins in health and disease. Data pertaining to thousands of protein-protein interactions, posttranslational modifications, enzyme/substrate relationships, disease associations, tissue expression, and subcellular localization were extracted from the literature for a nonredundant set of 2750 human proteins. Almost all the information was obtained manually by biologists who read and interpreted >300,000 published articles during the annotation process. This database, which has an intuitive query interface allowing easy access to all the features of proteins, was built by using open source technologies and will be freely available at http://www.hprd.org to the academic community. This unified bioinformatics platform will be useful in cataloging and mining the large number of proteomic interactions and alterations that will be discovered in the postgenomic era.

BRCA1 Protein↗