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Peter Uetz

Publications and source records attributed to Peter Uetz.

16 recordsLinked to original sources
PubMed2006

Novel conserved assembly factor of the bacterial flagellum.

TP0658 (FliW) and its orthologs, conserved proteins of unknown function in Treponema pallidum and other species, interact with a C-terminal region of flagellin (FlaB1-3 in T. pallidum; FliC in most other species). Mutants of orthologs in Bacillus subtilis and Campylobacter jejuni (yviF, CJ1075) showed strongly reduced motility. TP0658 stabilizes flagellin in a way similar to FliS, suggesting that TP0658 is a conserved assembly factor for the bacterial flagellum.

Bacillus subtilis↗
PubMed2006

Transcriptional activators in yeast.

Eukaryotic transcription activation domains (ADs) are not well defined on the proteome scale. We systematicallly tested approximately 6000 yeast proteins for transcriptional activity using a yeast one-hybrid system and identified 451 transcriptional activators. We then determined their transcription activation strength using fusions to the Gal4 DNA-binding domain and a His3 reporter gene which contained a promoter with a Gal4-binding site. Among the 132 strongest activators 32 are known transcription factors while another 35 have no known function. Although zinc fingers, helix-loop-helix domains and several other domains are highly overrepresented among the activators, only few contain characterized ADs. We also found some striking correlations: the stronger the activation activity, the more acidic, glutamine-rich, proline-rich or asparagine-rich the activators were. About 29% of the activators have been found previously to specifically interact with the transcription machinery, while 10% are known to be components of transcription regulatory complexes. Based on their transcriptional activity, localization and interaction patterns, at least six previously uncharacterized proteins are suggested to be bona fide transcriptional regulators (namely YFL049W, YJR070C, YDR520C, YGL066W/Sgf73, YKR064W and YCR082W/Ahc2).

Amino Acids↗
PubMed2006

The elusive yeast interactome.

Simple eukaryotic cells such as yeast could contain around 800 protein complexes, as two new comprehensive studies show. But slightly different approaches resulted in surprising differences between the two datasets, showing that more work is required to get a complete picture of the yeast interactome.

Genome, Fungal↗
PubMed2005

Herpesviral protein networks and their interaction with the human proteome.

The comprehensive yeast two-hybrid analysis of intraviral protein interactions in two members of the herpesvirus family, Kaposi sarcoma-associated herpesvirus (KSHV) and varicella-zoster virus (VZV), revealed 123 and 173 interactions, respectively. Viral protein interaction networks resemble single, highly coupled modules, whereas cellular networks are organized in separate functional submodules. Predicted and experimentally verified interactions between KSHV and human proteins were used to connect the viral interactome into a prototypical human interactome and to simulate infection. The analysis of the combined system showed that the viral network adopts cellular network features and that protein networks of herpesviruses and possibly other intracellular pathogens have distinguishing topologies.

Cell Line↗
PubMed2005

From protein networks to biological systems.

A system-level understanding of any biological process requires a map of the relationships among the various molecules involved. Technologies to detect and predict protein interactions have begun to produce very large maps of protein interactions, some including most of an organism's proteins. These maps can be used to study how proteins work together to form molecular machines and regulatory pathways. They also provide a framework for constructing predictive models of how information and energy flow through biological networks. In many respects, protein interaction maps are an entrée into systems biology.

Animals↗
PubMed2005

Conserved patterns of protein interaction in multiple species.

To elucidate cellular machinery on a global scale, we performed a multiple comparison of the recently available protein-protein interaction networks of Caenorhabditis elegans, Drosophila melanogaster, and Saccharomyces cerevisiae. This comparison integrated protein interaction and sequence information to reveal 71 network regions that were conserved across all three species and many exclusive to the metazoans. We used this conservation, and found statistically significant support for 4,645 previously undescribed protein functions and 2,609 previously undescribed protein interactions. We tested 60 interaction predictions for yeast by two-hybrid analysis, confirming approximately half of these. Significantly, many of the predicted functions and interactions would not have been identified from sequence similarity alone, demonstrating that network comparisons provide essential biological information beyond what is gleaned from the genome.

Amino Acid Sequence↗
PubMed2004

Ubiquitin-like protein Hub1 is required for pre-mRNA splicing and localization of an essential splicing factor in fission yeast.

Hub1/Ubl5 is a member of the family of ubiquitin-like proteins (UBLs). The tertiary structure of Hub1 is similar to that of ubiquitin; however, it differs from known modifiers in that there is no conserved glycine residue near the C terminus which, in ubiquitin and UBLs, is required for covalent modification of target proteins. Instead, there is a conserved dityrosine motif proximal to the terminal nonconserved amino acid. In S. cerevisiae, high molecular weight adducts can be formed in vivo from Hub1, but the structure of these adducts is not known, and they could be either covalent or noncovalent. The budding yeast HUB1 gene is not essential, but Delta hub1 mutants display defects in mating. Here, we report that fission yeast hub1 is an essential gene, whose loss results in cell cycle defects and inefficient pre-mRNA splicing. A screen for Hub1 interactors identified Snu66, a component of the U4/U6.U5 tri-snRNP splicing complex. Furthermore, overexpression of Snu66 suppresses the lethality of a hub1ts mutant. In cells lacking functional hub1, the nuclear localization of Snu66 is disrupted, suggesting that an important role for Hub1 is the correct subcellular targeting of Snu66, although our data suggest that Hub1 is likely to perform other roles in splicing as well.

Cell Cycle↗
PubMed2004

The spindle pole body assembly component mps3p/nep98p functions in sister chromatid cohesion.

For successful chromosome segregation during mitosis, several processes must occur early in the cell cycle, including spindle pole duplication, DNA replication, and the establishment of cohesion between nascent sister chromatids. Spindle pole body duplication begins in G1 and continues during early S-phase as spindle pole bodies mature and start to separate. Key steps in spindle pole body duplication are the sequential recruitment of Cdc31p and Spc42p by the nuclear envelope transmembrane protein Msp3p/Nep98p (herein termed Mps3p). Concurrent with DNA replication, Ctf7p/Eco1p (herein termed Ctf7p) ensures that nascent sister chromatids are paired together, identifying the products of replication as sister chromatids. Here, we provide the first evidence that the nuclear envelope spindle pole body assembly component Mps3p performs a function critical to sister chromatid cohesion. Mps3p was identified as interacting with Ctf7p from a genome-wide two-hybrid screen, and the physical interaction was confirmed by both in vivo (co-immunoprecipitation) and in vitro (GST pull-down) assays. An in vivo cohesion assay on new mps3/nep98 alleles revealed that loss of Mps3p results in precocious sister chromatid separation and that Mps3p functions after G1, coincident with Ctf7p. Mps3p is not required for cohesion during mitosis, revealing that Mps3p functions in cohesion establishment and not maintenance. Mutated Mps3p that results in cohesion defects no longer binds to Ctf7p in vitro, demonstrating that the interaction between Mps3p and Ctf7p is physiologically relevant. In support of this model, mps3 ctf7 double mutant cells exhibit conditional synthetic lethality. These findings document a new role for Mps3p in sister chromatid cohesion and provide novel insights into the mechanism by which a spindle pole body component, when mutated, contributes to aneuploidy.

Acetyltransferases↗
PubMed2004

The phox homology (PX) domain protein interaction network in yeast.

The phox homology (PX) domain is a phosphoinositide-binding domain that is conserved from yeast to human. Here we show for the first time by genome-wide two-hybrid screens and in vitro binding assays that the PX domain is a bona fide protein interaction domain. The yeast PX domain-only proteins Grd19p (YOR357C) and Ypt35p (YHR105W), as well as the isolated PX domains from Mvp1p (YMR004W), Snx42p/Cvt20p/Atg20p (YDL113C), Vam7p (YGL212W), and Vps17p (YOR132W), yielded a total of 40 reproducible two-hybrid interactions. Thirty-five interactions were found for the full-length proteins of Bem1p (YBR200W), Snx42p, Snx4p/Cvt13p (YJL036W), Vam7p, Vps5p (YOR069W), and Vps17p, but these appear not to require the PX domain, because these interactions could not be reproduced with PX-only baits. Interactions of Grd19p, Vam7p, Vps5p, Vps17p, and Ypt35p with members of the Yip1p family of proteins were detected consistently and were verified by in vitro binding assays. The N-terminal cytoplasmic domain of Yip1p and Yif1p mediates these interactions with PX domains. A mutation in the lipid-binding pocket of Ypt35p that reduces lipid binding markedly does not affect these PX domain protein interactions, arguing that lipid binding uses a different interaction surface than protein binding.

Binding Sites↗
PubMed2004

From ORFeomes to protein interaction maps in viruses.

Although cloned viral ORFeomes are particularly well suited for genome-wide interaction mapping due to the limited size of viral genomes, only a few such studies have been published. Here, we summarize virus interaction mapping projects involving vaccinia virus, hepatitis C virus (HCV), potato virus A (PVA), pea seed-borne mosaic virus (PSbMV), and bacteriophage T7, as well as some projects in progress. The studies reported suggest that virus-specific coding and replication strategies must be taken into account to yield accurate numbers of protein interactions. In particular, the number of false negatives can be significant for RNA viruses expressing precursor polyproteins (because interactions between full-length mature proteins are often not detected due to incorrect processing) and for viruses replicating in the cytoplasm whose transcripts have not been selected for splicing signals. In conclusion, the studies on viral protein interaction maps suggest that cloned pathogen ORFeomes will contribute to a holistic picture of the pathogenesis of infectious diseases and are ideal starting points for new approaches in systems biology. Both viral ORFeome and interaction mapping projects are being documented on our Web site (http://itgmv1.fzk.de/www/itg/uetz/virus/).

Cloning, Molecular↗
PubMed2004

What do we learn from high-throughput protein interaction data?

The biological significance of protein interactions, their method of generation and reliability is briefly reviewed. Protein interaction networks adopt a scale-free topology that explains their error tolerance or vulnerability, depending on whether hubs or peripheral proteins are attacked. Networks also allow the prediction of protein function from their interaction partners and therefore, the formulation of analytical hypotheses. Comparative network analysis predicts interactions for distantly related species based on conserved interactions, even if sequences are only weakly conserved. Finally, the medical relevance of protein interaction analysis is discussed and the necessity for data integration is emphasized.

Animals↗
PubMed2003

The yeast G protein alpha subunit Gpa1 transmits a signal through an RNA binding effector protein Scp160.

In yeast Saccharomyces cerevisiae the G protein betagamma subunits (Ste4/Ste18) have long been known to transmit the signal required for mating. Here we demonstrate that GTPase-deficient mutants of Galpha (Gpa1) directly activate the mating response pathway. We also show that signaling by activated Gpa1 requires direct coupling to an RNA binding protein Scp160. These findings suggest an additional role for Gpa1 and reveal Scp160 as a component of the mating response pathway in yeast.

Dose-Response Relationship, Drug↗
PubMed2002

Regulation of stress response signaling by the N-terminal dishevelled/EGL-10/pleckstrin domain of Sst2, a regulator of G protein signaling in Saccharomyces cerevisiae.

All members of the regulator of G protein signaling (RGS) family contain a conserved core domain that can accelerate G protein GTPase activity. The RGS in yeast, Sst2, can inhibit a G protein signal leading to mating. In addition, some RGS proteins contain an N-terminal domain of unknown function. Here we use complementary whole genome analysis methods to investigate the function of the N-terminal Sst2 domain. To identify a signaling pathway regulated by N-Sst2, we performed genome-wide transcription profiling of cells expressing this fragment alone and found differences in 53 transcripts. Of these, 40 are induced by N-Sst2, and nearly all contain a stress response element (STRE) in the promoter region. To identify components of a signaling pathway leading from N-Sst2 to STREs, we performed a genome-wide two-hybrid analysis using N-Sst2 as bait and found 17 interacting proteins. To identify the functionally relevant interacting proteins, we analyzed all of the available gene deletion mutants and found three (vps36 Delta, pep12 Delta, and tlg2 Delta) that induce STRE and also repress pheromone-dependent transcription. We selected VPS36 for further characterization. A vps36 Delta mutation diminishes signaling by pheromone as well as by downstream components including the G protein, effector kinase (Ste11), and transcription factor (Ste12). Conversely, overexpression of Vps36 enhances the pheromone response in sst2 Delta cells but not in wild type. These findings indicate that Vps36 and Sst2 have opposite and opposing effects on the pheromone and stress response pathways, with Vps36 acting downstream of the G protein and independently of Sst2 RGS activity.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Two-hybrid arrays.

The two-hybrid system is a genetic method for detecting protein-protein interactions. The assay can be applied to random libraries or arrays of colonies that express defined pairs of proteins. Arrays enable the testing of all possible protein pairs for interactions in a systematic fashion. The array format makes a large number of individual assays comparable and thus greatly simplifies the identification of false positives. Two-hybrid arrays have been used to study interactions among the proteins of yeast, hepatitis C virus, vaccinia virus, Drosophila, Caenorhabditis elegans, mouse and other species, and have already identified thousands of interactions.

Animals↗