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Stuart Milstein

Publications and source records attributed to Stuart Milstein.

9 recordsLinked to original sources

hORFeome v3.1: a resource of human open reading frames representing over 10,000 human genes.

Complete sets of cloned protein-encoding open reading frames (ORFs), or ORFeomes, are essential tools for large-scale proteomics and systems biology studies. Here we describe human ORFeome version 3.1 (hORFeome v3.1), currently the largest publicly available resource of full-length human ORFs (available at ). Generated by Gateway recombinational cloning, this collection contains 12,212 ORFs, representing 10,214 human genes, and corresponds to a 51% expansion of the original hORFeome v1.1. An online human ORFeome database, hORFDB, was built and serves as the central repository for all cloned human ORFs (http://horfdb.dfci.harvard.edu). This expansion of the original ORFeome resource greatly increases the potential experimental search space for large-scale proteomics studies, which will lead to the generation of more comprehensive datasets.

Animals↗

C. elegans GLA-3 is a novel component of the MAP kinase MPK-1 signaling pathway required for germ cell survival.

During oocyte development in Caenorhabditis elegans, approximately half of all developing germ cells undergo apoptosis. While this process is evolutionarily conserved from worms to humans, the regulators of germ cell death are still largely unknown. In a genetic screen for novel genes involved in germline apoptosis in Caenorhabditis elegans, we identified and cloned gla-3. Loss of gla-3 function results in increased germline apoptosis and reduced brood size due to defective pachytene exit from meiosis I. gla-3 encodes a TIS11-like zinc-finger-containing protein that is expressed in the germline, from the L4 larval stage to adulthood. Biochemical evidence and genetic epistasis analysis revealed that GLA-3 participates in the MAPK signaling cascade and directly interacts with the C. elegans MAPK MPK-1, an essential meiotic regulator. Our results show that GLA-3 is a new component of the MAPK cascade that controls meiotic progression and apoptosis in the C. elegans germline and functions as a negative regulator of the MAPK signaling pathway during vulval development and in muscle cells.

Animals↗

From genome to proteome: developing expression clone resources for the human genome.

cDNA clones have long been valuable reagents for studying the structure and function of proteins. With recent access to the entire human genome sequence, it has become possible and highly productive to compare the sequences of mRNAs to their genes, in order to validate the sequences and protein-coding annotations of each (1,2). Thus, well-characterized collections of human cDNAs are now playing an essential role in defining the structure and function of human genes and proteins. In this review, we will summarize the major collections of human cDNA clones, discuss some limitations common to most of these collections and describe several noteworthy proteomics applications, focusing on the detection and analysis of protein-protein interactions (PPI). These human cDNA collections contain principally two types of cDNA clones. The largest collections comprise cDNAs with full-length protein coding sequences (FL-CDS). Some but not all of these cDNA clones may represent the entire mRNA sequence, but many are missing considerable non-coding UTR sequence, usually at the 5' end. A second type of cDNA clone, a 'full-ORF' (F-ORF) expression clone, is one where the annotated protein-coding sequence, excised of 5' UTR and 3' UTR sequence, has been transferred to a vector designed to facilitate transfer to other vectors for protein expression.

Cloning, Molecular↗

Towards a proteome-scale map of the human protein-protein interaction network.

Systematic mapping of protein-protein interactions, or 'interactome' mapping, was initiated in model organisms, starting with defined biological processes and then expanding to the scale of the proteome. Although far from complete, such maps have revealed global topological and dynamic features of interactome networks that relate to known biological properties, suggesting that a human interactome map will provide insight into development and disease mechanisms at a systems level. Here we describe an initial version of a proteome-scale map of human binary protein-protein interactions. Using a stringent, high-throughput yeast two-hybrid system, we tested pairwise interactions among the products of approximately 8,100 currently available Gateway-cloned open reading frames and detected approximately 2,800 interactions. This data set, called CCSB-HI1, has a verification rate of approximately 78% as revealed by an independent co-affinity purification assay, and correlates significantly with other biological attributes. The CCSB-HI1 data set increases by approximately 70% the set of available binary interactions within the tested space and reveals more than 300 new connections to over 100 disease-associated proteins. This work represents an important step towards a systematic and comprehensive human interactome project.

Cloning, Molecular↗

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↗

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↗

C. elegans ORFeome version 3.1: increasing the coverage of ORFeome resources with improved gene predictions.

The first version of the Caenorhabditis elegans ORFeome cloning project, based on release WS9 of Wormbase (August 1999), provided experimental verifications for approximately 55% of predicted protein-encoding open reading frames (ORFs). The remaining 45% of predicted ORFs could not be cloned, possibly as a result of mispredicted gene boundaries. Since the release of WS9, gene predictions have improved continuously. To test the accuracy of evolving predictions, we attempted to PCR-amplify from a highly representative worm cDNA library and Gateway-clone approximately 4200 ORFs missed earlier and for which new predictions are available in WS100 (May 2003). In this set we successfully cloned 63% of ORFs with supporting experimental data ("touched" ORFs), and 42% of ORFs with no supporting experimental evidence ("untouched" ORFs). Approximately 2000 full-length ORFs were cloned in-frame, 13% of which were corrected in their exon/intron structure relative to WS100 predictions. In total, approximately 12,500 C. elegans ORFs are now available as Gateway Entry clones for various reverse proteomics (ORFeome v3.1). This work illustrates why the cloning of a complete C. elegans ORFeome, and likely the ORFeomes of other multicellular organisms, needs to be an iterative process that requires multiple rounds of experimental validation together with gradually improving gene predictions.

Animals↗

Caenorhabditis elegans HUS-1 is a DNA damage checkpoint protein required for genome stability and EGL-1-mediated apoptosis.

BACKGROUND: The inability to efficiently repair DNA damage or remove cells with severely damaged genomes has been linked to several human cancers. Studies in yeasts and mammals have identified several genes that are required for proper activation of cell cycle checkpoints following various types of DNA damage. However, in metazoans, DNA damage can induce apoptosis as well. How DNA damage activates the apoptotic machinery is not fully understood. RESULTS: We demonstrate here that the Caenorhabditis elegans gene hus-1 is required for DNA damage-induced cell cycle arrest and apoptosis. Following DNA damage, HUS-1 relocalizes and forms distinct foci that overlap with chromatin. Relocalization does not require the novel checkpoint protein RAD-5; rather, relocalization appears more frequently in rad-5 mutants, suggesting that RAD-5 plays a role in repair. HUS-1 is required for genome stability, as demonstrated by increased frequency of spontaneous mutations, chromosome nondisjunction, and telomere shortening. Finally, we show that DNA damage increases expression of the proapoptotic gene egl-1, a response that requires hus-1 and the p53 homolog cep-1. CONCLUSIONS: Our findings suggest that the RAD-5 checkpoint protein is not required for HUS-1 to relocalize following DNA damage. Furthermore, our studies reveal a new function of HUS-1 in the prevention of telomere shortening and mortalization of germ cells. DNA damage-induced germ cell death is abrogated in hus-1 mutants, in part, due to the inability of these mutants to activate egl-1 transcription in a cep-1/p53-dependent manner. Thus, HUS-1 is required for p53-dependent activation of a BH3 domain protein in C. elegans.

Amino Acid Sequence↗