News from an Ancient World: Two Novel Astacin Metalloproteases from the Horseshoe Crab

In this work, we report the cloning, heterologous expression, and characterization of two novel astacin proteases from the chelicerate Limulus polyphemus (horseshoe crab), designated as LAST (Limulus astacin) and LAST_MAM (Limulus astacin containing a MAM domain), respectively. The expression pattern showed ubiquitous occurrence of LAST_MAM, while LAST was predominantly restricted to the eyes and brain, indicating a function in the nervous system. Both enzymes contain the characteristic metzincin-type zinc-binding region and Met turn. While LAST is made up only of the typical prodomain and astacin-like protease domain, LAST_MAM contains an additional MAM (meprin A5 protein tyrosine phosphat…

Proteomic Analyses Reveal an Acidic Prime Side Specificity for the Astacin Metalloprotease Family Reflected by Physiological Substrates

Astacins are secreted and membrane-bound metalloproteases with clear associations to many important pathological and physiological processes. Yet with only a few substrates described their biological roles are enigmatic. Moreover, the lack of knowledge of astacin cleavage site specificities hampers assay and drug development. Using PICS (proteomic identification of protease cleavage site specificity) and TAILS (terminal amine isotopic labeling of substrates) degradomics approaches >3000 cleavage sites were proteomically identified for five different astacins. Such broad coverage enables family-wide determination of specificities N- and C-terminal to the scissile peptide bond. Remarkably, me…

Enhanced Activity of Meprin-α, a Pro-Migratory and Pro-Angiogenic Protease, in Colorectal Cancer

Meprin-α is a metalloprotease overexpressed in cancer cells, leading to the accumulation of this protease in a subset of colorectal tumors. The impact of increased meprin-α levels on tumor progression is not known. We investigated the effect of this protease on cell migration and angiogenesis in vitro and studied the expression of meprin-α mRNA, protein and proteolytic activity in primary tumors at progressive stages and in liver metastases of patients with colorectal cancer, as well as inhibitory activity towards meprin-α in sera of cancer patient as compared to healthy controls. We found that the hepatocyte growth factor (HGF)- induced migratory response of meprin-transfected epithelial c…

The C-terminal region of human plasma fetuin-B is dispensable for the raised-elephant-trunk mechanism of inhibition of astacin metallopeptidases

© The Author(s) 2019.

Transglutaminase-1 and Bathing Suit Ichthyosis: Molecular Analysis of Gene/Environment Interactions

The α and β Subunits of the Metalloprotease Meprin Are Expressed in Separate Layers of Human Epidermis, Revealing Different Functions in Keratinocyte Proliferation and Differentiation

The zinc endopeptidase meprin (EC 3.4.24.18) is expressed in brush border membranes of intestine and kidney tubules, intestinal leukocytes, and certain cancer cells, suggesting a role in epithelial differentiation and cell migration. Here we show by RT-PCR and immunoblotting that meprin is also expressed in human skin. As visualized by immunohistochemistry, the two meprin subunits are localized in separate cell layers of the human epidermis. Meprin alpha is expressed in the stratum basale, whereas meprin beta is found in cells of the stratum granulosum just beneath the stratum corneum. In hyperproliferative epidermis such as in psoriasis vulgaris, meprin alpha showed a marked shift of expre…

Meprins, membrane-bound and secreted astacin metalloproteinases

The astacins are a subfamily of the metzincin superfamily of metalloproteinases. The first to be characterized was the crayfish enzyme astacin. To date more than 200 members of this family have been identified in species ranging from bacteria to humans. Astacins are involved in developmental morphogenesis, matrix assembly, tissue differentiation and digestion. Family members include the procollagen C-proteinase (BMP1, bone morphogenetic protein 1), tolloid and mammalian tolloid-like, HMP (Hydra vulgaris metalloproteinase), sea urchin BP10 (blastula protein) and SPAN (Strongylocentrotus purpuratus astacin), the 'hatching' subfamily comprising alveolin, ovastacin, LCE, HCE ('low' and 'high' c…

Heteroaromatic Inhibitors of the Astacin Proteinases Meprin α, Meprin β and Ovastacin Discovered by a Scaffold-Hopping Approach.

Abstract Astacin metalloproteinases, in particular meprins α and β, as well as ovastacin, are emerging drug targets. Drug‐discovery efforts have led to the development of the first potent and selective inhibitors in the last few years. However, the most recent compounds are based on a highly flexible tertiary amine scaffold that could cause metabolic liabilities or decreased potency due to the entropic penalty upon binding to the target. Thus, the aim of this study was to discover novel conformationally constrained scaffolds as starting points for further inhibitor optimization. Shifting from flexible tertiary amines to rigid heteroaromatic cores resulted in a boost in inhibitory activity. …

Fetuin-B, a liver-derived plasma protein is essential for fertilization.

SummaryThe zona pellucida (ZP) is a glycoprotein matrix surrounding mammalian oocytes. Upon fertilization, ZP hardening prevents sperm from binding to and penetrating the ZP. Here, we report that targeted gene deletion of the liver-derived plasma protein fetuin-B causes premature ZP hardening and, consequently, female infertility. Transplanting fetuin-B-deficient ovaries into wild-type recipients restores fertility, indicating that plasma fetuin-B is necessary and sufficient for fertilization. In vitro fertilization of oocytes from fetuin-B-deficient mice only worked after rendering the ZP penetrable by laser perforation. Mechanistically, fetuin-B sustains fertility by inhibiting ovastacin,…

Insect Cells for Heterologous Production of Recombinant Proteins

Heterologous gene expression has become an indispensable and powerful tool for the production and subsequent functional analysis of proteins that are difficult to purify from their natural sources. Furthermore, it is the method of choice for the production of variants by introducing site-specific mutations into the DNA encoding the protein of interest. However, many systems are biased by disadvantages. The inability of bacteria to confer important post-translational modifications often results in functional failure of the recombinant protein. In addition, disulfide bonds are not formed properly in bacterial systems. Mammalian cells on the other hand modify properly, but they generally provi…

Handling Metalloproteinases.

Substrate cleavage by metalloproteinases involves nucleophilic attack on the scissile peptide bond by a water molecule that is polarized by a catalytic metal, usually a zinc ion, and a general base, usually the carboxyl group of a glutamic acid side chain. The zinc ion is most often complexed by imidazole nitrogens of histidine side chains. This arrangement suggests that the physiological pH optimum of most metalloproteinases is in the neutral range. In addition to their catalytic metal ion, many metalloproteinases contain additional transition metal or alkaline earth ions, which are structurally important or modulate the catalytic activity. As a consequence, these enzymes are generally sen…

Structural basis for the sheddase function of human meprin β metalloproteinase at the plasma membrane.

Ectodomain shedding at the cell surface is a major mechanism to regulate the extracellular and circulatory concentration or the activities of signaling proteins at the plasma membrane. Human meprin β is a 145-kDa disulfide-linked homodimeric multidomain type-I membrane metallopeptidase that sheds membrane-bound cytokines and growth factors, thereby contributing to inflammatory diseases, angiogenesis, and tumor progression. In addition, it cleaves amyloid precursor protein (APP) at the β-secretase site, giving rise to amyloidogenic peptides. We have solved the X-ray crystal structure of a major fragment of the meprin β ectoprotein, the first of a multidomain oligomeric transmembrane sheddase…

Two α subunits and one β subunit of meprin zinc-endopeptidases are differentially expressed in the zebrafish Danio rerio

Abstract Meprins are members of the astacin family of metalloproteases expressed in epithelial tissues, intestinal leukocytes and certain cancer cells. In mammals, there are two homologous subunits, which form complex glycosylated disulfide-bonded homo- and heterooligomers. Both human meprin α and meprin β cleave several basement membrane components, suggesting a role in epithelial differentiation and cell migration. There is also evidence that meprin β is involved in immune defence owing to its capability of activating interleukin-1β and the diminished mobility of intestinal leukocytes in meprin β-knockout mice. Here we show for the first time by reverse transcription PCR, immunoblotting a…

Additional file 11 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 11: Fig. S9. Uncropped Western blot and gel images

The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Abstract Background The Hydra head organizer acts as a signaling center that initiates and maintains the primary body axis in steady state polyps and during budding or regeneration. Wnt/beta-Catenin signaling functions as a primary cue controlling this process, but how Wnt ligand activity is locally restricted at the protein level is poorly understood. Here we report a proteomic analysis of Hydra head tissue leading to the identification of an astacin family proteinase as a Wnt processing factor. Results Hydra astacin-7 (HAS-7) is expressed from gland cells as an apical-distal gradient in the body column, peaking close beneath the tentacle zone. HAS-7 siRNA knockdown abrogates HyWnt3 proteo…

Primary Evaluation of Potential Small Molecule Inhibitors of the Astacin Metalloproteinase Ovastacin, A Novel Drug Target in Female Infertility Treatment

<p>Despite huge progress in hormonal therapy and improved in vitro fertilization methods, the success rates in infertility treatment are still limited. A recently discovered mechanism revealed the interplay between the plasma protein fetuin-B and the cortical granule-based proteinase ovastacin as novel key-mechanism in the regulation of fertilization. Upon sperm-egg fusion, cleavage of a distinct zona pellucida component by ovastacin destroys the sperm receptor, enhances zona robustness and eventually provides a definitive block against polyspermy. An untimely onset of this zona hardening prior to fertilization would consequently result in infertility. Physiologically, this process is…

The interaction of recombinant subdomains of the procollagen C-proteinase with procollagen I provides a quantitative explanation for functional differences between the two splice variants, mammalian tolloid and bone morphogenetic protein 1.

The procollagen C-proteinase (PCP) is a zinc peptidase of the astacin family and the metzincin superfamily. The enzyme removes the C-terminal propeptides of fibrillar procollagens and activates other matrix proteins. Besides its catalytic protease domain, the procollagen C-proteinase contains several C-terminal CUB modules (named after complement factors C1r and C1s, the sea urchin UEGF protein, and BMP-1) and EGF-like domains. The two major splice forms of the C-proteinase differ in their overall domain composition. The longer variant, termed mammalian tolloid (mTld, i.e., PCP-2), has the protease- CUB1-CUB2-EGF1-CUB3-EGF2-CUB4-CUB5 composition, whereas the shorter form termed bone morphog…

A Primary Evaluation of Potential Small-Molecule Inhibitors of the Astacin Metalloproteinase Ovastacin, a Novel Drug Target in Female Infertility Treatment.

Abstract Despite huge progress in hormonal therapy and improved in vitro fertilization methods, the success rates in infertility treatment are still limited. A recently discovered mechanism revealed the interplay between the plasma protein fetuin‐B and the cortical granule‐based proteinase ovastacin to be a novel key mechanism in the regulation of fertilization. Upon sperm–egg fusion, cleavage of a distinct zona pellucida component by ovastacin destroys the sperm receptor, enhances zona robustness, and eventually provides a definitive block against polyspermy. An untimely onset of this zona hardening prior to fertilization would consequently result in infertility. Physiologically, this proc…

Astacin

The protease domain of procollagen C-proteinase (BMP1) lacks substrate selectivity, which is conferred by non-proteolytic domains.

Abstract Procollagen C-proteinase (PCP) removes the C-terminal pro-peptides of procollagens and also processes other matrix proteins. The major splice form of the PCP is termed BMP1 (bone morphogenetic protein 1). Active BMP1 is composed of an astacin-like protease domain, three CUB (complement, sea urchin Uegf, BMP1) domains and one EGF-like domain. Here we compare the recombinant human full-length BMP1 with its isolated proteolytic domain to further unravel the functional influence of the CUB and EGF domains. We show that the protease domain alone cleaves truncated procollagen VII within the short telopeptide region into fragments of similar size as the full-length enzyme does. However, u…

Proenzyme Structure and Activation of Astacin Metallopeptidase

Proteolysis is regulated by inactive (latent) zymogens, with a prosegment preventing access of substrates to the active-site cleft of the enzyme. How latency is maintained often depends on the catalytic mechanism of the protease. For example, in several families of the metzincin metallopeptidases, a >cysteine switch> mechanism involves a conserved prosegment motif with a cysteine residue that coordinates the catalytic zinc ion. Another family of metzincins, the astacins, do not possess a cysteine switch, so latency is maintained by other means. We have solved the high resolution crystal structure of proastacin from the European crayfish, Astacus astacus. Its prosegment is the shortest struc…

Sizzled Is Unique among Secreted Frizzled-related Proteins for Its Ability to Specifically Inhibit Bone Morphogenetic Protein-1 (BMP-1)/Tolloid-like Proteinases

BMP-1/tolloid-like proteinases (BTPs) are major enzymes involved in extracellular matrix assembly and activation of bioactive molecules, both growth factors and anti-angiogenic molecules. Although the control of BTP activity by several enhancing molecules is well established, the possibility that regulation also occurs through endogenous inhibitors is still debated. Secreted frizzled-related proteins (sFRPs) have been studied as possible candidates, with highly contradictory results, after the demonstration that sizzled, a sFRP found in Xenopus and zebrafish, was a potent inhibitor of Xenopus and zebrafish tolloid-like proteases. In this study, we demonstrate that mammalian sFRP-1, -2, and …

Meprins process matrix metalloproteinase-9 (MMP-9)/gelatinase B and enhance the activation kinetics by MMP-3

Abstract Meprin α and β, members of the astacin family of zinc metalloproteinases, are unique plasma membrane and secreted proteases known to cleave a wide range of biological substrates involved in inflammation, cancer and fibrosis. In this study, we identified proMMP-9 as a novel substrate and show that aminoterminal meprin-mediated clipping improves the activation kinetics of proMMP-9 by MMP-3, an efficient activator of proMMP-9. Interestingly, the NH2-terminus LVLFPGDL, generated by incubation with meprin α, is identical to the form produced in conditioned media from human neutrophils and monocytes. Hence, this meprin-mediated processing and enhancement of MMP-9 activation kinetics may …

The E-modulus of the oocyte is a non-destructive measure of zona pellucida hardening

Reproduction 162(4), 259-266 (2021). doi:10.1530/REP-21-0122

Specific processing of tenascin-C by the metalloprotease meprinβ neutralizes its inhibition of cell spreading

The metalloprotease meprin has been implicated in tissue remodelling due to its capability to degrade extracellular matrix components. Here, we investigated the susceptibility of tenascin-C to cleavage by meprinbeta and the functional properties of its proteolytic fragments. A set of monoclonal antibodies against chicken and human tenascin-C allowed the mapping of proteolytic fragments generated by meprinbeta. In chicken tenascin-C, meprinbeta processed all three major splicing variants by removal of 10kDa N-terminal and 38kDa C-terminal peptides, leaving a large central part of subunits intact. A similar cleavage pattern was found for large human tenascin-C variant where two N-terminal pep…

Identification and characterization of onchoastacin, an astacin-like metalloproteinase from the filaria Onchocerca volvulus

Abstract The tissue-invasive nematode Onchocerca volvulus causes skin and eye pathology in human onchocerciasis. While the adult females reside sessile in subcutaneous nodules, the microfilariae are abundantly released from the nodules, males and juvenile worms migrate through the host tissue. Matrix-degrading metallo- and serine proteinases have been detected in excretory-secretory worm products that may be essential for migration of the mobile stages. In this study, a 1713 bp long cDNA encoding for a putative proteinase of O. volvulus has been isolated. The predicted protein sequence includes a signal peptide indicating secretion to the extracellular space, a propeptide, an astacin-like p…

Procollagen C-proteinase Enhancer Stimulates Procollagen Processing by Binding to the C-propeptide Region Only*

Background: Procollagen C-proteinase enhancer-1 (PCPE-1) is an extracellular glycoprotein that increases activity of certain zinc metalloproteinases involved in tissue development and repair. Results: PCPE-1 binds uniquely to the C-propeptide region of the procollagen molecule. Conclusion: PCPE-1 enhances proteolysis by binding solely to the procollagen C-propeptides. Significance: These data may lead to future applications in the development of antifibrotic therapies.

Astacins: proteases in development and tissue differentiation

Capítulo en: Stöker, Walter; Brix, Klaudia (eds.). Proteases: structure and function. Wien: Springer, 2013

Fetuin-A and Cystatin C Are Endogenous Inhibitors of Human Meprin Metalloproteases

Meprin α and β, zinc metalloproteinases, play significant roles in inflammation, including inflammatory bowel disease (IBD), possibly by activating cytokines, like interleukin 1β, interleukin 18, or tumor growth factor α. Although a number of potential activators for meprins are known, no endogenous inhibitors have been identified. In this work, we analyzed the inhibitory potential of human plasma and identified bovine fetuin-A as an endogenous meprin inhibitor with a K(i) (inhibition constant) of 4.2 × 10(-5) M for meprin α and a K(i) of 1.1 × 10(-6) M meprin β. This correlated with data obtained for a fetuin-A homologue from carp (nephrosin inhibitor) that revealed a potent meprin α and β…

Additional file 12 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 12: Table S3. LNA and RNA probe sequences used for WISH.

Functional and structural insights into astacin metallopeptidases

The astacins are a family of multi-domain metallopeptidases with manifold functions in metabolism. They are either secreted or membrane-anchored and are regulated by being synthesized as inactive zymogens and also by colocalizing protein inhibitors. The distinct family members consist of N-terminal signal peptides and pro-segments, zincdependent catalytic domains, further downstream extracellular domains, transmembrane anchors, and cytosolic domains. The catalytic domains of four astacins and the zymogen of one of these have been structurally characterized and shown to comprise compact ~200-residue zinc-dependent moieties divided into an N-terminal and a C-terminal sub-domain by an active-s…

Let it flow: Morpholino knockdown in zebrafish embryos reveals a pro-angiogenic effect of the metalloprotease meprin alpha2.

BACKGROUND: Meprin metalloproteases are thought to be involved in basic physiological functions such as cell proliferation and tissue differentiation. However, the specific functions of these enzymes are still ambiguous, although a variety of growth factors and structural proteins have been identified as meprin substrates. The discovery of meprins alpha(1), alpha(2) and beta in teleost fish provided the basis for uncovering their physiological functions by gene silencing in vivo. METHODOLOGY/PRINCIPAL FINDINGS: A Morpholino knockdown in zebrafish embryos targeting meprin alpha(1) and beta mRNA caused defects in general tissue differentiation. But meprin alpha(2) morphants were affected more…

The crystal structure of a 250-kDa heterotetrameric particle explains inhibition of sheddase meprin β by endogenous fetuin-B

Meprin β (Mβ) is a multidomain type-I membrane metallopeptidase that sheds membrane-anchored substrates, releasing their soluble forms. Fetuin-B (FB) is its only known endogenous protein inhibitor. Herein, we analyzed the interaction between the ectodomain of Mβ (MβΔC) and FB, which stabilizes the enzyme and inhibits it with subnanomolar affinity. The MβΔC:FB crystal structure reveals a ∼250-kDa, ∼160-Å polyglycosylated heterotetrameric particle with a remarkable glycan structure. Two FB moieties insert like wedges through a “CPDCP trunk” and two hairpins into the respective peptidase catalytic domains, blocking the catalytic zinc ions through an “aspartate switch” mechanism. Uniquely, the …

Mammalian plasma fetuin-B is a selective inhibitor of ovastacin and meprin metalloproteinases

AbstractVertebrate fetuins are multi-domain plasma-proteins of the cystatin-superfamily. Human fetuin-A is also known as AHSG, α2-Heremans-Schmid-glycoprotein. Gene-knockout in mice identified fetuin-A as essential for calcified-matrix-metabolism and bone-mineralization. Fetuin-B deficient mice, on the other hand, are female infertile due to zona pellucida ‘hardening’ caused by the metalloproteinase ovastacin in unfertilized oocytes. In wildtype mice fetuin-B inhibits the activity of ovastacin thus maintaining oocytes fertilizable. Here we asked, if fetuins affect further proteases as might be expected from their evolutionary relation to single-domain-cystatins, known as proteinase-inhibito…

Propeptide glycosylation and galectin‐3 binding decrease proteolytic activation of human proMMP‐9/progelatinase B

Matrix metalloproteinases (MMPs) are secreted as proenzymes, containing propeptides that interact with the catalytic zinc, thereby controlling MMP activation. The MMP‐9 propeptide is unique in the MMP family because of its post‐translational modification with an N‐linked oligosaccharide. ProMMP‐9 activation by MMP‐3 occurs stepwise by cleavage of the propeptide in an aminoterminal (pro‐AT) and carboxyterminal (pro‐CT) peptide. We chemically synthesized aglycosyl pro‐AT and pro‐CT and purified recombinant glycosylated pro‐ATS f−9. First, we report new cleavage sites in the MMP‐9 propeptide by MMP‐3 and neutrophil elastase. Additionally, we demonstrated with the use of western blot analysis a…

Additional file 13 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 13: Table S4. siRNA and qPCR primer sequences.

Metalloprotease meprin beta in rat kidney: glomerular localization and differential expression in glomerulonephritis

Meprin (EC 3.4.24.18) is an oligomeric metalloendopeptidase found in microvillar membranes of kidney proximal tubular epithelial cells. Here, we present the first report on the expression of meprin beta in rat glomerular epithelial cells and suggest a potential involvement in experimental glomerular disease. We detected meprin beta in glomeruli of immunostained rat kidney sections on the protein level and by quantitative RT-PCR of laser-capture microdissected glomeruli on the mRNA level. Using immuno-gold staining we identified the membrane of podocyte foot processes as the main site of meprin beta expression. The glomerular meprin beta expression pattern was altered in anti-Thy 1.1 and pas…

Other astacin homologs

Publisher Summary This chapter describes the activity, specificity and structural chemistry of astacin homologs. The astacins are members of the metzincin superfamily such as the serralysins, the reprolysins/adamalysins, the matrixins, the leishmanolysins, the pregnancy-associated plasma proteins, the snapalysins and the fragilysins. Proteins of the hatching subfamily have been shown to be important for the cleavage of membranes coating developing embryos of invertebrates and vertebrates. Other members of this subfamily have varying or even several functions. UVS.2 from Xenopus, originally shown to play a role in dorso-anterior development, has been identified as the frog hatching enzyme. T…

Processing of procollagen III by meprins: new players in extracellular matrix assembly?

Meprins α and β, a subgroup of zinc metalloproteinases belonging to the astacin family, are known to cleave components of the extracellular matrix, either during physiological remodeling or in pathological situations. In this study we present a new role for meprins in matrix assembly, namely the proteolytic processing of procollagens. Both meprins α and β release the N- and C-propeptides from procollagen III, with such processing events being critical steps in collagen fibril formation. In addition, both meprins cleave procollagen III at exactly the same site as the procollagen C-proteinases, including bone morphogenetic protein-1 (BMP-1) and other members of the tolloid proteinase family. …

Intracellular activation of ovastacin mediates pre-fertilization hardening of the zona pellucida

Study question How and where is pro-ovastacin activated and how does active ovastacin regulate zona pellucida hardening (ZPH) and successful fertilization? Study finding Ovastacin is partially active before exocytosis and pre-hardens the zona pellucida (ZP) before fertilization. What is known already The metalloproteinase ovastacin is stored in cortical granules, it cleaves zona pellucida protein 2 (ZP2) upon fertilization and thereby destroys the ZP sperm ligand and triggers ZPH. Female mice deficient in the extracellular circulating ovastacin-inhibitor fetuin-B are infertile due to pre-mature ZPH. Study design, samples/materials, methods We isolated oocytes from wild-type and ovastacin-de…

Additional file 2 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 2: Table S1. (a) Secretome of Hydra HL HyWnt3 (+) fraction. (b) Secretome of Hydra HL HyWnt3 (-) fraction.

Additional file 3 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 3: Table S2. Complete proteome data of HyWnt3(+) and HyWnt3(-) HL fractions.

Limited proteolysis by acrosin affects sperm-binding and mechanical resilience of the mouse zona pellucida.

Abstract The encounter of oocyte and sperm is the key event initiating embryonic development in mammals. Crucial functions of this existential interaction are determined by proteolytic enzymes, such as acrosin, carried in the sperm head acrosome, and ovastacin, stored in the oocyte cortical granules. Ovastacin is released upon fertilisation to cleave the zona pellucida, a glycoprotein matrix surrounding the oocyte. This limited proteolysis hardens the oocyte envelope, and thereby provides a definitive block against polyspermy and protects the developing embryo. On the other hand, acrosin, the renowned and most abundant acrosomal protease, has been thought to enable sperm to penetrate the oo…

Additional file 10 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 10: Fig. S8. Developmental balance between ectopic structures. (a) siHAS-7/siNdr electroporation blocks ectopic axis formation after subsequent AZK treatment. (b-c) siHAS-7/Wnt8 electroporation and AZK treatment reduces ectopic tentacle development in double axis animals (b) and leads to multiple secondary axis formation in a fraction of the treated animals (c). Red arrows denote secondary axes. The asterisk denotes the peduncle region. (d) Ectopic tentacle inhibition is clearly evident in animals electroporated with siWnt8 followed by AZK treatment. Note that few residual ectopic tentacles are detectable in c and d mostly on the side not directly hit by the electroporation …

Additional file 5 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 5: Fig. S3. Expression of HAS genes in the interstitial stem cell cluster. (a) t-SNE representation of interstitial cells with clusters labeled by cell state as presented in [25]. (b) Interstitial cell cluster annotation of HyDkk1/2/4 and ataxin genes identified in HyWnt3(+) head lysate fraction. The cells in the t-SNE plots were colored based on expression levels for the respective gene. The transcript IDs are as follows: HMP1: t1098aep, HAS-1: t20535aep, HAS-2: t18494aep, HAS-3: t22149aep, HAS-4: t11453aep, HAS-5: t596aep, HAS-6: t19593aep, HAS-7: t16296aep, HAS-8: t22154aep, HAS-9: t3416aep, HAS-10: t10258aep, HAS-11: t19316aep. HyDkk1/2/4: t8678aep. Cluster label abbrevi…

Additional file 6 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 6: Fig. S4. Detection of HAS-7 by Western blot. (a) Antigenic peptide competition demonstrates the specificity of the HAS-7 antibody. A Western blot for tissue lysates as in Fig. 3a was performed using primary antibody solution with (right panel) or without (left panel) 1 mg/ml of the antigenic peptide used for generating the HAS-7 antibody. The HAS-7 peptide effectively reduces the detection of specific bands at ~ 40 and 70 kDa. (b) Ni-NTA affinity purified recombinant HAS-7. Separation by 12% SDS-PAGE was followed by staining with Coomassie brilliant blue (left) or transfer to PVDF and immunodetection (right) using the Penta-His-antibody as described above. For each lane 1…

Additional file 8 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 8: Fig. S6. Representative images of knockdown and transgenic phenotypes. Representative images of HAS-7 siRNA treated (a-c), HAS-7 siRNA/AZK treated (d-g) or transgenic actin::HyWnt3 (h-i) animals. Scale bars: 200 μm. The inset in Fig. S6a shows an early stage of ectopic axis formation recorded 4 days after electroporation. Red arrows indicate the hypostome areas of the two heads.

Additional file 7 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 7: Fig. S5. Evidence for normal function and morphology of ectopic heads and tentacles. (a-b) Both heads in a HAS-7 siRNA treated animal with a double axis are able to capture and feed on artemia. The arrow denotes an ectopic foot induced by the secondary head. Scale bars = 500 μm. (c-e) Ectopic tentacles induced by ALP treatment show anatomic and molecular features of functional tentacles as demonstrated by immunocytochemistry using a nematocyst-specific antibody (anti-CPP-1) [53]. CPP-1 is a structural component of mature nematocysts in battery cells of tentacles. (c) Overview of CPP-1-stained hydra with ectopic tentacles. Scale bar = 200 μm. (d-e) Enlargement from boxed a…

Additional file 1 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 1: Fig. S1. Ion exchange chromatogram of hydra head lysate pool. (a) 7 fractions of 0.5 ml exceeding an absorption unit threshold of 0.175 were collected as indicated. The cut-off was chosen to provide a critical total protein concentration (> 80 μg) for the subsequent proteome analysis. (b) Peak fractions from (a) were re-screened for HyWnt3-His processing activity. A fragment of Hydra cadherin extracellular domain comprising the first two N-terminal cadherin repeats (HmCadherin1-2) was used as control substrate to monitor unspecific matrix metalloproteinase activity. Accordingly, fractions 4-5 were pooled and analyzed by mass spectrometry as HyWnt3-His(+) sample, fracti…

Additional file 14 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 14: The individual data values for Figs. 3f and 5f.

Additional file 9 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 9: Fig. S7. Function of HAS-7 in regeneration. Animals bisected after HAS-7 siRNA electroporation do not show axis duplication in head (a-b) or foot (c-d) regenerates. Animals were bisected at 50% of body length at day 6 after electroporation and documented at day 0 (a, c) and day 4 (b, d) after bisection. Representatives of 25 bisected hydras examined. Scale bars: 200 μm. (e) Heat map showing the dynamics of transcript levels for HyWnt3(+) astacin genes compared to HyWnt3 and beta-Catenin. Only components that were significantly differentially expressed (P

Additional file 4 of The Wnt-specific astacin proteinase HAS-7 restricts head organizer formation in Hydra

Additional file 4: Fig. S2. Phylogenetic tree of astacin metalloproteinases established by PhyLM 3.0 (SEAVIEW package) and based on an alignment of the catalytic domains only, omitting pro-sequences and multiple C-terminal domains. Numbers indicate probability values (in %) obtained from 100 bootstrap replications. Protein abbreviations from bottom: fAST, flavastacin (Flavobacterium meningosepticum, i.e. Chryseobacterium meningosepticum, i.e. Elisabethkingia meningoseptica, Q47899, used as outgroup); HEA-1, Hydractinia echinata astacin-1 (Q2MCX9); HEA-3, H. echinata astacin-3 (Q2MCX7); HEA-4, H. echinata astacin-4 (Q2MCX6); HMP1, Hydra vulgaris metalloproteinase-1 (NP_001296695.1), AST, ast…