Kato Y et al. (2002) J Biol Chem "Determinants of ligand specificity in groups I and IV WW domains as studied by surface plasmon resonance and model building."

Kato Y, Ito M, Tanokura M, Kawai K, Nagata K

[J Biol Chem, 2002]

WW domains are universal protein modules for binding Pro-rich ligands. They are classified into four groups according to their binding specificity. Arg-14 and Arg-17, on the WW domain of Pin1, are thought to be important for the binding of Group IV ligands that have (Ser(P)/Thr(P))-Pro sequences. We have applied surface plasmon resonance to determine the ligand specificity of several WW domains containing Arg-14. Among these WW domains, Rsp5.2 and mNedd4.3 bound only to the Group I ligand containing Pro-Pro-Xaa-Tyr with K(D) values of 11 and 55 microm, respectively. The WW domains of hPin1, Caenorhabditis elegans Pin1 homologue (Y110), PinA, and SspI bound to Group IV ligands with K(D) values ranging from 22 to 700 microm. PinA and SspI do not have Arg-17, unlike Pin1 and Y110. The modeled structures of the WW domains of PinA and SspI revealed that the structure and the network of hydrogen bonds of Loop I, which are also formed in Pin1 and Y110, are conserved. We propose that this configuration of Loop I (referred to as the "p patch") is necessary for binding Group IV ligands and that it can be used to predict the specificity and functions of other WW domains.

Wright GM et al. (2019) Nucleic Acids Res "The nucleosome position-encoding WW/SS sequence pattern is depleted in mammalian genes relative to other eukaryotes."

Cui F, Wright GM

[Nucleic Acids Res, 2019]

Nucleosomal DNA sequences generally follow a well-known pattern with 10-bp periodic WW (where W is A or T) dinucleotides that oscillate in phase with each other and out of phase with SS (where S is G or C) dinucleotides. However, nucleosomes with other DNA patterns have not been systematically analyzed. Here, we focus on an opposite pattern, namely anti-WW/SS pattern, in which WW dinucleotides preferentially occur at DNA sites that bend into major grooves and SS (where S is G or C) dinucleotides are often found at sites that bend into minor grooves. Nucleosomes with the anti-WW/SS pattern are widespread and exhibit a species- and context-specific distribution in eukaryotic genomes. Unlike non-mammals (yeast, nematode and fly), there is a positive correlation between the enrichment of anti-WW/SS nucleosomes and RNA Pol II transcriptional levels in mammals (mouse and human). Interestingly, such enrichment is not due to underlying DNA sequence. In addition, chromatin remodeling complexes have an impact on the abundance but not on the distribution of anti-WW/SS nucleosomes in yeast. Our data reveal distinct roles of cis- and trans-acting factors in the rotational positioning of nucleosomes between non-mammals and mammals. Implications of the anti-WW/SS sequence pattern for RNA Pol II transcription are discussed.

Sayanova O et al. (1997) Proc Natl Acad Sci U S A "Expression of a borage desaturase cDNA containing an N-terminal cytochrome b5 domain results in the accumulation of high levels of delta6-desaturated fatty acids in transgenic tobacco."

Stobart AK, Smith MA, Napier JA, Lapinskas P, Christie WW, Dobson G, Sayanova O, Shewry PR

[Proc Natl Acad Sci U S A, 1997]

gamma-Linolenic acid (GLA; C18:3 delta(6,9,12)) is a component of the seed oils of evening primrose (Oenothera spp.), borage (Borago officinalis L.), and some other plants. It is widely used as a dietary supplement and for treatment of various medical conditions. GLA is synthesized by a delta6-fatty acid desaturase using linoleic acid (C18:2 delta(9,12)) as a substrate. To enable the production of GLA in conventional oilseeds, we have isolated a cDNA encoding the delta6-fatty acid desaturase from developing seeds of borage and confirmed its function by expression in transgenic tobacco plants. Analysis of leaf lipids from a transformed plant demonstrated the accumulation of GLA and octadecatetraenoic acid (C18:4 delta(6,9,12,15)) to levels of 13.2% and 9.6% of the total fatty acids, respectively. The borage delta6-fatty acid desaturase differs from other desaturase enzymes, characterized from higher plants previously, by the presence of an N-terminal domain related to cytochrome b5.

Serizay J et al. (2020) Genome Res "Distinctive regulatory architectures of germline-active and somatic genes in C. elegans."

Dong Y, Serizay J, Chesney M, Cerrato C, Ahringer J, Janes J

[Genome Res, 2020]

RNA profiling has provided increasingly detailed knowledge of gene expression patterns, yet the different regulatory architectures that drive them are not well understood. To address this, we profiled and compared transcriptional and regulatory element activities across five tissues of <i>C. elegans</i>, covering ~90% of cells. We find that the majority of promoters and enhancers have tissue-specific accessibility, and we discover regulatory grammars associated with ubiquitous, germline and somatic tissue-specific gene expression patterns. In addition, we find that germline-active and soma-specific promoters have distinct features. Germline-active promoters have well positioned +1 and -1 nucleosomes associated with a periodic 10-bp WW signal (W = A/T). Somatic tissue-specific promoters lack positioned nucleosomes and this signal, have wide nucleosome depleted regions, and are more enriched for core promoter elements, which differ between tissues. We observe the 10-bp periodic WW signal at ubiquitous promoters in other animals suggesting it is an ancient conserved signal. Our results demonstrate fundamental differences in regulatory architectures of germline and somatic tissue-specific genes, uncover regulatory rules for generating diverse gene expression patterns, and provide a tissue-specific resource for future studies.

Courbard JR et al. (2002) J Biol Chem "Interaction between two ubiquitin-protein isopeptide ligases of different classes, CBLC and AIP4/ITCH."

Birnbaum D, Fiore F, Borg JP, Ollendorff V, Courbard JR, Adelaide J

[J Biol Chem, 2002]

In metazoans, CBL proteins are RING finger type ubiquitin-protein isopeptide (E3) ligases involved in the down-regulation of epidermal growth factor tyrosine kinase receptors (EGFR). Among the three CBL proteins described in humans, CBLC (CBL3) remains poorly studied. By screening in parallel a human and a Caenorhabditis elegans library using the two-hybrid procedure in yeast, we found a novel interaction between Hsa-CBLC and Hsa-AIP4 or its C. elegans counterpart Cel-WWP1. Hsa-AIP4 and Cel-WWP1 are also ubiquitin E3 ligases. They contain a HECT (homologous to E6-AP C terminus) catalytic domain and four WW domains known to bind proline-rich regions. We confirmed the interaction between Hsa-CBLC and Hsa-AIP4 by a combination of glutathione S-transferase pull-down, co-immunoprecipitation, and colocalization experiments. We show that these two E3 ligases are involved in EGFR signaling because both become phosphorylated on tyrosine following epidermal growth factor stimulation. In addition, we observed that CBLC increases the ubiquitination of EGFR, and that coexpressing the WW domains of AIP4 exerts a dominant negative effect on EGFR ubiquitination. Finally, coexpressing CBLC and AIP4 induces a down-regulation of EGFR signaling. In conclusion, our data demonstrate that two E3 ligases of different classes can interact and cooperate to down-regulate EGFR signaling.

Huang K et al. (2000) Gene "A HECT domain ubiquitin ligase closely related to the mammalian protein WWP1 is essential for Caenorhabditis elegans embryogenesis."

Mosser EA, Bresnick EH, Petcherski AG, Johnson KD, Kimble JE, Vandergon T, Huang K, Jenkins NA, Copeland NG

[Gene, 2000]

The highly conserved ubiquitin/proteasome pathway controls the degradation of many critical regulatory proteins. Proteins are posttranslationally conjugated to ubiquitin through a concerted set of reactions involving activating (E1), conjugating (E2), and ligase (E3) enzymes. Ubiquitination targets proteins for proteolysis via the proteasome and may regulate protein function independent of proteolysis. We describe the cloning and functional analysis of new members of the HECT domain family of E3 ubiquitin ligases. Murine Wwp1 encoded a broadly expressed protein containing a C2 domain, four WW domains, and a catalytic HECT domain. A Caenorhabditis elegans gene was cloned encoding a HECT domain protein (CeWWP1), which was highly homologous to murine and human WWP1. Disruption of CeWwp1 via RNA interference yielded an embryonic lethal phenotype, despite the presence of at least six additional C. elegans genes encoding HECT domain proteins. The embryonic lethality was characterized by grossly abnormal morphogenesis during late embryogenesis, despite normal proliferation early in embryogenesis. CeWWP1 must therefore have unique and nonredundant functions critical for embryogenesis.

Chen CS et al. (2010) PLoS One "WWP-1 is a novel modulator of the DAF-2 insulin-like signaling network involved in pore-forming toxin cellular defenses in Caenorhabditis elegans."

Chen HD, Aroian RV, Chen CS, Bellier A, Kao CY, Los FC, Yang YL

[PLoS One, 2010]

Pore-forming toxins (PFTs) are the single largest class of bacterial virulence factors. The DAF-2 insulin/insulin-like growth factor-1 signaling pathway, which regulates lifespan and stress resistance in Caenorhabditis elegans, is known to mutate to resistance to pathogenic bacteria. However, its role in responses against bacterial toxins and PFTs is as yet unexplored. Here we reveal that reduction of the DAF-2 insulin-like pathway confers the resistance of Caenorhabditis elegans to cytolitic crystal (Cry) PFTs produced by Bacillus thuringiensis. In contrast to the canonical DAF-2 insulin-like signaling pathway previously defined for aging and pathogenesis, the PFT response pathway diverges at 3-phosphoinositide-dependent kinase 1 (PDK-1) and appears to feed into a novel insulin-like pathway signal arm defined by the WW domain Protein 1 (WWP-1). In addition, we also find that WWP-1 not only plays an important role in the intrinsic cellular defense (INCED) against PFTs but also is involved in innate immunity against pathogenic bacteria Pseudomonas aeruginosa and in lifespan regulation. Taken together, our data suggest that WWP-1 and DAF-16 function in parallel within the fundamental DAF-2 insulin/IGF-1 signaling network to regulate fundamental cellular responses in C. elegans.

Holbert S et al. (2001) Proc Natl Acad Sci U S A "The Gln-Ala repeat transcriptional activator CA150 interacts with huntingtin: neuropathologic and genetic evidence for a role in Huntington's disease pathogenesis."

Holbert S, Ferrante RJ, Kiechle T, Hayden MR, Ross CA, Dausset J, Denghien I, Wellington C, Margolis RL, Neri C, Rosenblatt A

[Proc Natl Acad Sci U S A, 2001]

Huntington's disease (HD) is a neurodegenerative disease caused by polyglutamine expansion on the protein huntingtin (htt). Pathogenesis in HD appears to involve the formation of ubiquitinated neuronal intranuclear inclusions containing N-terminal mutated htt, abnormal protein interactions, and the aggregate sequestration of a variety of proteins (noticeably, transcription factors). To identify novel htt-interacting proteins in a simple model system, we used a yeast two-hybrid screen with a Caenorhabditis elegans activation domain library. We found a predicted WW domain protein (ZK1127.9) that interacts with N-terminal fragment of htt in two-hybrid tests. A human homologue of ZK1127.9 is CA150, a transcriptional coactivator with a N-terminal insertion that contains an imperfect (Gln-Ala) tract encoded by a polymorphic repeat DNA. CA150 interacted in vitro with full-length htt from lymphoblastoid cells. The expression of CA150, measured immunohistochemically, was markedly increased in human HD brain tissue compared with normal age-matched human brain tissue, and CA150 showed aggregate formation with partial colocalization to ubiquitin-positive aggregates. In 432 HD patients, the CA150 repeat length explains a small, but statistically significant, amount of the variability in the onset age. Our data suggest that abnormal expression of CA150, mediated by interaction with polyglutamine-expanded htt, may alter transcription and have a role in HD

Brasher BB et al. (2001) Oncogene "Mutational analysis of the regulatory function of the c-Abl Src homology 3 domain."

Roumiantsev S, Van Etten RA, Brasher BB

[Oncogene, 2001]

The catalytic activity of the c-Abl tyrosine kinase is tightly regulated by its Src homology 3 (SH3) domain through a complex mechanism that may involve intramolecular binding to Pro242 in the linker region between the SH2 and catalytic domains as well as interactions with a trans-inhibitor. We analysed the effect of mutation or replacement of SH3 on c-Abl tyrosine kinase activity and transformation. Random mutagenesis of SH3 identified several novel point mutations that dysregulated c-Abl kinase activity in vivo, but the RT loop was insensitive to mutational activation. Activating SH3 mutations abolished binding of proline-rich SH3 ligands in vitro, while mutations at Ser140 in the connector between the SH3 and SH2 domains activated Abl kinase activity in vivo and in vitro but did not impair SH3 ligand-binding. Abl was regulated efficiently when its SH3 domain was replaced with a heterologous SH3 from c-Src that binds a different spectrum of proline-rich ligands, but not by substitution of a modular WW domain with similar ligand-binding specificity. These results suggest that the SH3 domain regulates Abl principally by binding to the atypical intramolecular ligand Pro242 rather than a canonical PxxP ligand. Coordination between the SH3 and SH2 domains mediated by the connector region may be required for regulation of Abl even in the absence of SH2 ligand binding.

Mesrouze Y et al. (2020) Protein Sci "Study of the TEAD-binding domain of the YAP protein from animal species."

Erdmann D, Chene P, Zimmermann C, Mesrouze Y, Bokhovchuk F, Fontana P, Meyerhofer M

[Protein Sci, 2020]

The Hippo signaling pathway, which plays a central role in the control of organ size in animals, is well conserved in metazoans. The most downstream elements of this pathway are the TEAD transcription factors that are regulated by their association with the transcriptional coactivator YAP. Therefore, the creation of the binding interface that ensures the formation of the YAP:TEAD complex is a critical molecular recognition event essential for the development/survival of many living organisms. In this report, using the available structural information on the YAP:TEAD complex, we study the TEAD-binding domain of YAP from different animal species. This analysis of more than 400 amino acid sequences reveals that the residues from YAP involved in the formation of the two main contact regions with TEAD are very well conserved. Therefore, the binding interface between YAP and TEAD, as found in humans, probably appeared at an early evolutionary stage in metazoans. We find that, in contrast to most other animal species, several Actinopterygii species possess YAP variants with a different TEAD-binding domain. However, these variants bind to TEAD with a similar affinity. Our studies show that the protein identified as a YAP homolog in Caenorhabditis elegans does not contain the TEAD-binding domain found in YAP of other metazoans. Finally, we do not identify in non-metazoan species, amino acid sequences containing both a TEAD-binding domain, as in metazoan YAP, and WW domain(s). This article is protected by copyright. All rights reserved.