K153R polymorphism in myostatin gene increases the rate of promyostatin activation by furin

Recent studies demonstrated an association between the K153R polymorphism in the myostatin gene with extreme longevity, lower muscle strength and obesity but the molecular basis of these associations has not been clarified. Here, we show that the K153R mutation significantly increases the rate of proteolysis of promyostatin by furin, but has no effect on the activity of the latent complex or the cleavage of the latent complex by bone morphogenetic protein 1 (BMP-1). The increased rate of activation of K153R mutant promyostatin may explain why this polymorphism is associated with obesity, lower muscle strength and extension of lifespan

Új, orvosbiológiai szempontból fontos moduláris fehérjék azonosítása, szerkezeti és funkcionális jellemzése = Identification and structure-function studies on novel medically important modular proteins

A gerincesekre jellemző moduláris fehérjék kitüntetett orvosbiológiai jelentősége miatt fontos ezeknek a fehérjéknek az azonosítása, funkciójuk tisztázása. 1.) Az általunk korábban azonosított WFIKKN1 és WFIKKN2 multidomén fehérjék közül a WFIKKN2 -ről ismert, hogy kötődik miosztatinhoz. SPR mérésekkel jellemeztük a fehérjék és doménjeik kölcsönhatását miosztatinnal. NMR spektroszkópiával meghatároztuk a WFIKKN1 második Kunitz típusú doménjének térszerkezetét. Az SPR mérések, a KU2 domén térszerkezete és a korábbi enzimkinetikai méréseink eredményei alapján valószinűnek tűnik, hogy a WFIKKN1 fehérje is egy TGF-beta családba tartozó fehérje aktivitásának szabályozásában játszik szerepet. 2.) Meghatároztuk a Wnt jelátvitelben részt vevő WIF-1 fehérje WIF doménjének térszerkezetét. A domén térszerkezetét az immunoglobulin domének szerkezetére emlékeztető 8 beta redő által alkotott szendvics szerkezet és két alfa helix jellemzi. Az NMR spektroszkópiai térszerkezet meghatározásokat Gottfried Otting munkacsoportjával együttműködésben végeztük. 3.) A bioinformatikai módszerekkel azonosított gének jelentős hányadáról bizonyosodik be, hogy megjósolt szerkezetük téves. Módszert dolgoztunk ki olyan fehérjék azonosítására, melyek szerkezete ellentmond alapvető fehérjeszerkezeti törvényszerűségeknek. A módszer alkalmas abnormális fehérjeformák azonosítására és lehetőséget nyújt a génpredikciós eljárások minőségellenőrzésére. Az elemzés menete a http://mispred.enzim.hu honlapon megtalálható. | 1.) Recently we have identified two novel proteins (WFIKKN1 and WFIKKN2) one of which (WFIKKN2) has been shown to bind to myostatin and inhibit myostatin activity. We have shown that - similarly to the homologous protein - WFIKKN1 also binds to myostatin and thus may also participate in the regulation of the activity of TGF-beta family members. 2.) In collaboration with the NMR group of Gottfried Otting we have determined the three-dimensional structure of the WIF domain of Wnt- Inhibitory-Factor-1. The fold consists of an eight-stranded beta-sandwich reminiscent of the immunoglobulin fold. 3.) The predicted structure of a significant proportion of the computationally predicted genes is incorrect, therefore we have developed tools for the identification of mispredicted genes. The rationale of this approach is that a gene is suspected to be mispredicted if some features of the encoded protein conflict with our current knowledge about proteins. With the help of this tool we have shown that a significant proportion of mRNAs produced by alternative splicing encode non-viable, aberrant proteins with no physiological role

Structure, function and disease relevance of Wnt inhibitory factor 1, a secreted protein controlling the Wnt and hedgehog pathways

Wnts and Hedgehogs (Hh) are large, lipid-modified extracellular morphogens that play key roles in embryonic development and stem cell proliferation of Metazoa. Both morphogens signal through heptahelical Frizzled-type receptors of the G-Protein Coupled Receptor family and there are several other similarities that suggest a common evolutionary origin of the Hh and Wnt pathways. There is evidence that the secreted protein, Wnt inhibitory factor 1 (WIF1) modulates the activity of both Wnts and Hhs and may thus contribute to the intertwining of these pathways. In this article, we review the structure, evolution, molecular interactions and functions of WIF1 with major emphasis on its role in carcinogenesis. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

Influence of WFIKKN1 on BMP1-mediated activation of latent myostatin

The NTR domain of WFIKKN1 protein has been shown to have significant affinity for the prodomain regions of promyostatin and latent myostatin but the biological significance of these interactions remained unclear. In view of its role as a myostatin antagonist, we tested the assumption that WFIKKN1 inhibits the release of myostatin from promyostatin and/or latent myostatin. WFIKKN1 was found to have no effect on processing of promyostatin by furin, the rate of cleavage of latent myostatin by BMP1, however, was significantly enhanced in the presence of WFIKKN1 and this enhancer activity was superstimulated by heparin. Unexpectedly, WFIKKN1 was also cleaved by BMP1 and our studies have shown that the KKN1 fragment generated by BMP1-cleavage of WFIKKN1 contributes most significantly to the observed enhancer activity. Analysis of a pro-TGF-β -based homology model of homodimeric latent myostatin revealed that the BMP1-cleavage sites are buried and not readily accessible to BMP1. In view of this observation, the most plausible explanation for the BMP1-enhancer activity of the KKN1 fragment is that it shifts a conformational equilibrium of latent myostatin from the closed circular structure of the homodimer to a more open form, making the cleavage sites more accessible to BMP1. On the other hand, the observation that the enhancer activity of KKN1 is superstimulated in the presence of heparin is explained by the fact KKN1, latent myostatin, and BMP1 have affinity for heparin and these interactions with heparin increase the local concentrations of the reactants thereby facilitating the action of BMP1. Enzymes: Furin: EC 3.4.21.75; BMP1, bone morphogentic protein 1 or procollagen C-endopeptidase: EC 3.4.24.19. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies

Morphological Stasis and Proteome Innovation in Cephalochordates

Lancelets, extant representatives of basal chordates, are prototypic examples of evolutionary stasis; they preserved a morphology and body-plan most similar to the fossil chordates from the early Cambrian. Such a low level of morphological evolution is in harmony with a low rate of amino acid substitution; cephalochordate proteins were shown to evolve slower than those of the slowest evolving vertebrate, the elephant shark. Surprisingly, a study comparing the predicted proteomes of Chinese amphioxus, Branchiostoma belcheri and the Florida amphioxus, Branchiostoma floridae has led to the conclusion that the rate of creation of novel domain combinations is orders of magnitude greater in lancelets than in any other Metazoa, a finding that contradicts the notion that high rates of protein innovation are usually associated with major evolutionary innovations. Our earlier studies on a representative sample of proteins have provided evidence suggesting that the differences in the domain architectures of predicted proteins of these two lancelet species reflect annotation errors, rather than true innovations. In the present work, we have extended these studies to include a larger sample of genes and two additional lancelet species, Asymmetron lucayanum and Branchiostoma lanceolatum. These analyses have confirmed that the domain architecture differences of orthologous proteins of the four lancelet species are because of errors of gene prediction, the error rate in the given species being inversely related to the quality of the transcriptome dataset that was used to aid gene prediction

A WFIKKN fehérjék és a miosztatin, GDF11 közötti kölcsönhatás jellemzése = Characterization of the interaction of WFIKKN1 and WFIKKN2 with Myostatin and GDF11.

Kimutattuk, hogy a WFIKKN fehérjék specifikus és hatékony inhibitorai a miosztatin/GDF8 és GDF11 növekedési faktoroknak. - Felületi plazmon rezonancia (SPR) mérésekkel megállapítottuk, hogy mindkét fehérje nagy affinitással (Kd ~ 10-8- 10-10M) köti a GDF8 és GDF11 növekedési faktorokat. A WFIKKN fehérjék elsősorban a follisztatin homológ (FS) doménjük révén kötik a miosztatint, de a netrin homológ (NTR) domén is részt vesz a kölcsönhatás kialakításában. - Kompeticiós SPR mérésekkel kimutattuk, hogy a WFIKKN fehérjék hatékonyan gátolják a miosztatin és GDF11 kötődését a receptoruk, az Activin-Receptor IIb ligand-kötő doménjéhez. - A miosztatin és GDF11 jelátvitel detektálására alkalmas riporter rendszerben mindkét WFIKKN fehérje hatékonyan gátolta a miosztatin és GDF11 növekedési faktorok által kiváltott jelátvitelt. - SPR mérésekkel megállapítottuk, hogy a WFIKKN fehérjék jelentős affinitással (Kd ~ 10-7- 10-8M) kötnek több más, a TGF? családba tartozó növekedési faktort is: a TGF?1-t, BMP2-t, BMP4-t. Gyengébb kölcsönhatást detektáltunk a BMP3 és BMP8b-vel és nem volt mérhető kölcsönhatás az Aktivin A-val. - A WFIKKN fehérjék és a TGF?1, BMP2 és BMP4 növekedési faktorok közötti kölcsönhatás ellenére riporter vizsgálatokban a WFIKKN fehérjék nem gátolták a TGF?1, BMP2 és BMP4 által kváltott jelátvitelt. Összegezve: eredményeink azt mutatják, hogy a WFIKKN1 és WFIKKN2 a miosztatin és GDF11 növekedési faktorok specifikus inhibitorai. | We have shown that WFIKKN proteins are potent and specific inhibitors of myostatin/GDF8 and GDF11, since - surface plasmon resonance measurements revealed that both WFIKKN1 and WFIKKN2 have high affinity (Kd ~ 10-8- 10-10M) for myostatin/GDF8 and GDF11. The interactions are mediated primarily by the follistatin homolog domains of WFIKKN proteins, but their NTR domains also contribute to these protein-protein interactions. - competitive SPR measurements have shown that WFIKKN1 and WFIKKN2 inhibit the interaction of myostatin and GDF11 with the extracellular ligand-binding domain of their high affinity receptor, Activin receptor IIb. - in luciferase reporter assays both WFIKKN proteins are potent inhibitors of the signaling activity of myostatin and GDF11. - SPR interaction measurements with several additional representatives of TGF? family revealed that both WFIKKN1 and WFIKKN2 bind TGF?1, BMP2 and BMP4 with relatively high affinity (Kd ~ 10-7- 10-8 M). WFIKKN proteins showed weak affinity for growth factors BMP3 and BMP8b, and they did not bind to Activin A. - Despite their significant affinity for TGF?1, BMP2 and BMP4, in reporter assays neither WFIKKN1 nor WFIKKN2 inhibited the signaling activity of TGF?1, BMP2 and BMP4. In summary: our data indicate that WFIKKN proteins block the signalling activity of myostatin and GDF11 specifically and potently by sequestering these growth factors thereby preventing their binding to their receptors

Wnt fehérjék és Wnt receptorok = Interaction of Wnt proteins with receptors and antagonists

Arginine-scanning mutagenezis és CD spektroszkópia segítségével meghatároztuk a Wnt inhibitory factor-1 WIF-doménjének Wnt-kötőhelyét. Kimutattuk, hogy a Wnt-kötőhely egyik szubrégiója (melynek kialakításában a Ile25, Phe27 és Phe42 aminosavak vesznek részt) a Wnt fehérjék palmitoil csoportját köti, a kötőhely másik szubrégiója (melynek kialakításában a Tyr13, Trp15 és Leu32 aminosavak vesznek részt) a Wnt-k aminosav-oldalláncainak kötésében játszik fontos szerepet. Az a megfigyelésünk, hogy a Tyr13, Trp15 és Leu32 mutációja a WIF-domén Wnt5a affinitásának növekedéséhez, ugyanakkor a Wnt3a affinitásának csökkenéséhez vezet, azt jelzi, hogy ez a szubrégió fontos szerepet játszik a domén Wnt specifitásának meghatározásában. A Wnt specifitást meghatározó aminosavak azonosításával olyan WIF mutánsokat állíthatunk elő, melyekkel lehetőség nyílik a daganatos betegségekben kulcsszerepet játszó Wnt fehérjék szelektív gátlására. | We have localized the Wnt-binding site of the WIF-domain of Wnt inhibitory factor-1 by structure-guided arginine-scanning mutagenesis in combination with surface plasmon resonance assays. We have shown that the subregion of the Wnt-binding site defined by Ile25, Phe27 and Phe42 may bind the palmitoyl group of Wnt-s, the other subregion defined by residues Tyr13, Trp15 and Leu32, however, is critical for interactions with amino acid side-chains of Wnts. Our observation that substitution of these residues of WIF resulted in an increased affinity for Wnt5a, but decreased affinity for Wnt3a suggests that these residues may define the specificity spectrum of WIF for Wnts. These results hold promise for the more specific targeting of Wnt family members with WIF variants in various forms of cancer

Use of Publication Dynamics to Distinguish Cancer Genes and Bystander Genes

de Magalhães has shown recently that most human genes have several papers in PubMed mentioning cancer, leading the author to suggest that every gene is associated with cancer, a conclusion that contradicts the widely held view that cancer is driven by a limited number of cancer genes, whereas the majority of genes are just bystanders in carcinogenesis. We have analyzed PubMed to decide whether publication metrics supports the distinction of bystander genes and cancer genes. The dynamics of publications on known cancer genes followed a similar pattern: seminal discoveries triggered a burst of cancer-related publications that validated and expanded the discovery, resulting in a rise both in the number and proportion of cancer-related publications on that gene. The dynamics of publications on bystander genes was markedly different. Although there is a slow but continuous time-dependent rise in the proportion of papers mentioning cancer, this phenomenon just reflects the increasing publication bias that favors cancer research. Despite this bias, the proportion of cancer papers on bystander genes remains low. Here, we show that the distinctive publication dynamics of cancer genes and bystander genes may be used for the identification of cancer genes

Latent myostatin has significant activity and this activity is controlled more efficiently by WFIKKN1 than by WFIKKN2

Myostatin, a negative regulator of skeletal muscle growth, is produced from myostatin precursor by multiple steps of proteolytic processing. After cleavage by a furin-type protease, the propeptide and growth factor domains remain associated, forming a noncovalent complex, the latent myostatin complex. Mature myostatin is liberated from latent myostatin by bone morphogenetic protein 1/tolloid proteases. Here, we show that, in reporter assays, latent myostatin preparations have significant myostatin activity, as the noncovalent complex dissociates at an appreciable rate, and both mature and semilatent myostatin (a complex in which the dimeric growth factor domain interacts with only one molecule of myostatin propeptide) bind to myostatin receptor. The interaction of myostatin receptor with semilatent myostatin is efficiently blocked by WAP, Kazal, immunoglobulin, Kunitz and NTR domain-containing protein 1 or growth and differentiation factor-associated serum protein 2 (WFIKKN1), a large extracellular multidomain protein that binds both mature myostatin and myostatin propeptide [Kondas et al. (2008) J Biol Chem 283, 23677–23684]. Interestingly, the paralogous protein WAP, Kazal, immunoglobulin, Kunitz and NTR domain-containing protein 2 or growth and differentiation factor-associated serum protein 1 (WFIKKN2) was less efficient than WFIKKN1 as an antagonist of the interactions of myostatin receptor with semilatent myostatin. Our studies have shown that this difference is attributable to the fact that only WFIKKN1 has affinity for the propeptide domain, and this interaction increases its potency in suppressing the receptor- binding activity of semilatent myostatin. As the interaction of WFIKKN1 with various forms of myostatin permits tighter control of myostatin activity until myostatin is liberated from latent myostatin by bone morphogenetic protein 1/tolloid proteases, WFIKKN1 may have greater potential as an antimyostatic agent than WFIKKN2

Wnt Inhibitory Factor 1 Binds to and Inhibits the Activity of Sonic Hedgehog

The hedgehog (Hh) and Wnt pathways, crucial for the embryonic development and stem cell proliferation of Metazoa, have long been known to have similarities that argue for their common evolutionary origin. A surprising additional similarity of the two pathways came with the discovery that WIF1 proteins are involved in the regulation of both the Wnt and Hh pathways. Originally, WIF1 (Wnt Inhibitory Factor 1) was identified as a Wnt antagonist of vertebrates, but subsequent studies have shown that in Drosophila, the WIF1 ortholog serves primarily to control the distribution of Hh. In the present, work we have characterized the interaction of the human WIF1 protein with human sonic hedgehog (Shh) using Surface Plasmon Resonance spectroscopy and reporter assays monitoring the signaling activity of human Shh. Our studies have shown that human WIF1 protein binds human Shh with high affinity and inhibits its signaling activity efficiently. Our observation that the human WIF1 protein is a potent antagonist of human Shh suggests that the known tumor suppressor activity of WIF1 may not be ascribed only to its role as a Wnt inhibitor