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Mazen I, Kamel A, McElreavey K, Bashamboo A, Elaidy A, Abdel-Hamid MS. A Homozygous Missense Variant in Hedgehog Acyltransferase (HHAT) Gene Associated with 46,XY Gonadal Dysgenesis. Sex Dev 2023; 16:261-265. [PMID: 35045414 DOI: 10.1159/000520366] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 10/21/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Disorders of gonadal development represent a clinically and genetically heterogeneous group of DSD, and the etiology in many cases remains unknown, indicating that our knowledge of factors controlling sex determination is still limited. METHODS We describe a 46,XY DSD patient from Egypt. The patient was reared as female, born to consanguineous parents, and was referred to us at the age of 5 years because of ambiguous genitalia. On examination, the girl was microcephalic (head circumference -3 SD), but her height and weight were normal for her age and sex. RESULTS Exome sequencing identified a homozygous variant in the hedgehog acyltransferase (HHAT) gene, which encodes an enzyme that is required for multimerization and signaling potency of the hedgehog secreted proteins. The variant is a novel homozygous missense change c.1329C>A (p.N443K), located within transmembrane domain 9, which segregated with the phenotype in the family. DISCUSSION/CONCLUSION Our results expand the phenotypic spectrum associated with HHAT variants to include 46,XY gonadal dysgenesis and reinforce the role of exome sequencing in unraveling new genes that play a pivotal role in sexual development.
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Affiliation(s)
- Inas Mazen
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Alaa Kamel
- Department of Human Cytogenetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | | | - Anu Bashamboo
- Human Developmental Genetics, Institut Pasteur, Paris, France
| | - Aya Elaidy
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Mohamed S Abdel-Hamid
- Department of Medical Molecular Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
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Schonbrun AR, Resh MD. Hedgehog acyltransferase catalyzes a random sequential reaction and utilizes multiple fatty acyl-CoA substrates. J Biol Chem 2022; 298:102422. [PMID: 36030053 PMCID: PMC9513256 DOI: 10.1016/j.jbc.2022.102422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/17/2022] Open
Abstract
Sonic hedgehog (Shh) signaling is a key component of embryonic development and is a driving force in several cancers. Hedgehog acyltransferase (Hhat), a member of the membrane-bound O-acyltransferase family of enzymes, catalyzes the attachment of palmitate to the N-terminal cysteine of Shh, a posttranslation modification critical for Shh signaling. The activity of Hhat has been assayed in cells and in vitro, and cryo-EM structures of Hhat have been reported, yet several unanswered questions remain regarding the enzyme’s reaction mechanism, substrate specificity, and the impact of the latter on Shh signaling. Here, we present an in vitro acylation assay with purified Hhat that directly monitors attachment of a fluorescently tagged fatty acyl chain to Shh. Our kinetic analyses revealed that the reaction catalyzed by Hhat proceeds through a random sequential mechanism. We also determined that Hhat can utilize multiple fatty acyl-CoA substrates for fatty acid transfer to Shh, with comparable affinities and turnover rates for myristoyl-CoA, palmitoyl-CoA, palmitoleoyl-CoA, and oleoyl-CoA. Furthermore, we investigated the functional consequence of differential fatty acylation of Shh in a luciferase-based Shh reporter system. We found that the potency of the signaling response in cells was higher for Shh acylated with saturated fatty acids compared to monounsaturated fatty acids. These findings demonstrate that Hhat can attach fatty acids other than palmitate to Shh and suggest that heterogeneous fatty acylation has the potential to impact Shh signaling in the developing embryo and/or cancer cells.
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Affiliation(s)
- Adina R Schonbrun
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY; Gerstner Sloan Kettering Graduate School
| | - Marilyn D Resh
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY; Gerstner Sloan Kettering Graduate School; Biochemistry, Cell Biology and Molecular Biology Graduate Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY.
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3
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Andrei SA, Tate EW, Lanyon-Hogg T. Evaluating Hedgehog Acyltransferase Activity and Inhibition Using the Acylation-coupled Lipophilic Induction of Polarization (Acyl-cLIP) Assay. Methods Mol Biol 2022; 2374:13-26. [PMID: 34562239 DOI: 10.1007/978-1-0716-1701-4_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Palmitoylation of the Hedgehog family of proteins is a critical step in the Hedgehog signaling pathway and is performed by the membrane-bound O-acyltransferase enzyme Hedgehog acyltransferase (HHAT). Measurement of HHAT activity has traditionally relied on radiolabeled fatty acid substrates, which imposes considerable constraints on throughput, cost, and safety, consequently hindering the efficient identification and development of small-molecule HHAT inhibitors. The Acylation-coupled Lipophilic Induction of Polarisation (Acyl-cLIP) assay was recently developed in our lab as a novel platform to evaluate lipidation of peptides in real time and high throughput. In this chapter, we describe the isolation of active HHAT from HEK293a cells and application of the Acyl-cLIP assay to characterize HHAT inhibitors. Our methodology uses standard chemical biology lab equipment and yields high-quality kinetic data from minimal sample volumes. The assay uses standard 384-well plates and is easily adapted to medium- or high-throughput screening formats.
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Lanyon‐Hogg T, Ritzefeld M, Zhang L, Andrei SA, Pogranyi B, Mondal M, Sefer L, Johnston CD, Coupland CE, Greenfield JL, Newington J, Fuchter MJ, Magee AI, Siebold C, Tate EW. Photochemical Probe Identification of a Small-Molecule Inhibitor Binding Site in Hedgehog Acyltransferase (HHAT). Angew Chem Weinheim Bergstr Ger 2021; 133:13654-13659. [PMID: 38504937 PMCID: PMC10946827 DOI: 10.1002/ange.202014457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/26/2021] [Indexed: 03/21/2024]
Abstract
The mammalian membrane-bound O-acyltransferase (MBOAT) superfamily is involved in biological processes including growth, development and appetite sensing. MBOATs are attractive drug targets in cancer and obesity; however, information on the binding site and molecular mechanisms underlying small-molecule inhibition is elusive. This study reports rational development of a photochemical probe to interrogate a novel small-molecule inhibitor binding site in the human MBOAT Hedgehog acyltransferase (HHAT). Structure-activity relationship investigation identified single enantiomer IMP-1575, the most potent HHAT inhibitor reported to-date, and guided design of photocrosslinking probes that maintained HHAT-inhibitory potency. Photocrosslinking and proteomic sequencing of HHAT delivered identification of the first small-molecule binding site in a mammalian MBOAT. Topology and homology data suggested a potential mechanism for HHAT inhibition which was confirmed by kinetic analysis. Our results provide an optimal HHAT tool inhibitor IMP-1575 (K i=38 nM) and a strategy for mapping small molecule interaction sites in MBOATs.
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Affiliation(s)
| | | | - Leran Zhang
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | | | - Balazs Pogranyi
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | - Milon Mondal
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | - Lea Sefer
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | | | - Claire E. Coupland
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | | | | | | | - Anthony I. Magee
- National Heart & Lung InstituteImperial College LondonLondonSW7 2AZUK
| | - Christian Siebold
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | - Edward W. Tate
- Department of ChemistryImperial College LondonLondonW12 0BZUK
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5
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Lanyon‐Hogg T, Ritzefeld M, Zhang L, Andrei SA, Pogranyi B, Mondal M, Sefer L, Johnston CD, Coupland CE, Greenfield JL, Newington J, Fuchter MJ, Magee AI, Siebold C, Tate EW. Photochemical Probe Identification of a Small-Molecule Inhibitor Binding Site in Hedgehog Acyltransferase (HHAT)*. Angew Chem Int Ed Engl 2021; 60:13542-13547. [PMID: 33768725 PMCID: PMC8252026 DOI: 10.1002/anie.202014457] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/26/2021] [Indexed: 11/30/2022]
Abstract
The mammalian membrane-bound O-acyltransferase (MBOAT) superfamily is involved in biological processes including growth, development and appetite sensing. MBOATs are attractive drug targets in cancer and obesity; however, information on the binding site and molecular mechanisms underlying small-molecule inhibition is elusive. This study reports rational development of a photochemical probe to interrogate a novel small-molecule inhibitor binding site in the human MBOAT Hedgehog acyltransferase (HHAT). Structure-activity relationship investigation identified single enantiomer IMP-1575, the most potent HHAT inhibitor reported to-date, and guided design of photocrosslinking probes that maintained HHAT-inhibitory potency. Photocrosslinking and proteomic sequencing of HHAT delivered identification of the first small-molecule binding site in a mammalian MBOAT. Topology and homology data suggested a potential mechanism for HHAT inhibition which was confirmed by kinetic analysis. Our results provide an optimal HHAT tool inhibitor IMP-1575 (Ki =38 nM) and a strategy for mapping small molecule interaction sites in MBOATs.
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Affiliation(s)
| | | | - Leran Zhang
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | | | - Balazs Pogranyi
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | - Milon Mondal
- Department of ChemistryImperial College LondonLondonW12 0BZUK
| | - Lea Sefer
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | | | - Claire E. Coupland
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | | | | | | | - Anthony I. Magee
- National Heart & Lung InstituteImperial College LondonLondonSW7 2AZUK
| | - Christian Siebold
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordOX3 7BNUK
| | - Edward W. Tate
- Department of ChemistryImperial College LondonLondonW12 0BZUK
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Abstract
Hedgehog and Wnt proteins are modified by covalent attachment of the fatty acids palmitate and palmitoleate, respectively. These lipid modifications are essential for Hedgehog and Wnt protein signaling activities and are catalyzed by related, but distinct fatty acyltransferases: Hedgehog acyltransferase (Hedgehog) and Porcupine (Wnt). In this chapter, we provide detailed methods to directly monitor Hedgehog and Wnt protein fatty acylation in vitro. Palmitoylation of Sonic hedgehog (Shh), a representative Hedgehog family member, is assayed using purified Hedgehog acyltransferase (Hhat) or Hhat-enriched membranes, a recombinant 19 kDa Shh protein or C-terminally biotinylated Shh 10-mer peptide, and 125I-iodopalmitoyl CoA as the donor fatty acyl CoA substrate. The radiolabeled reaction products are quantified by SDS-PAGE and phosphorimaging or by γ-counting. To assay Wnt acylation, the reaction consists of a biotinylated, double disulfide-bonded Wnt peptide containing the sequence surrounding the Wnt3a acylation site, [125I] iodo-cis-9-pentadecenoyl CoA, and Porcupine-enriched membranes. Radiolabeled, biotinylated Wnt3a peptide is captured on streptavidin coated beads and the reaction product is quantified by γ-counting.
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Affiliation(s)
- James John Asciolla
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.,Biochemistry, Cell Biology and Molecular Biology Graduate Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Kalpana Rajanala
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Marilyn D Resh
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA. .,Biochemistry, Cell Biology and Molecular Biology Graduate Program, Weill-Cornell Graduate School of Medical Sciences, New York, NY, USA.
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Lanyon-Hogg T, Masumoto N, Bodakh G, Konitsiotis AD, Thinon E, Rodgers UR, Owens RJ, Magee AI, Tate EW. Synthesis and characterisation of 5-acyl-6,7-dihydrothieno[3,2-c]pyridine inhibitors of Hedgehog acyltransferase. Data Brief 2016; 7:257-81. [PMID: 27077078 PMCID: PMC4816282 DOI: 10.1016/j.dib.2016.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/19/2016] [Accepted: 02/02/2016] [Indexed: 11/25/2022] Open
Abstract
In this data article we describe synthetic and characterisation data for four members of the 5-acyl-6,7-dihydrothieno[3,2-c]pyridine (termed "RU-SKI") class of inhibitors of Hedgehog acyltransferase, including associated NMR spectra for final compounds. RU-SKI compounds were selected for synthesis based on their published high potencies against the enzyme target. RU-SKI 41 (9a), RU-SKI 43 (9b), RU-SKI 101 (9c), and RU-SKI 201 (9d) were profiled for activity in the related article "Click chemistry armed enzyme linked immunosorbent assay to measure palmitoylation by Hedgehog acyltransferase" (Lanyon-Hogg et al., 2015) [1]. (1)H NMR spectral data indicate different amide conformational ratios between the RU-SKI inhibitors, as has been observed in other 5-acyl-6,7-dihydrothieno[3,2-c]pyridines. The synthetic and characterisation data supplied in the current article provide validated access to the class of RU-SKI inhibitors.
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Affiliation(s)
- Thomas Lanyon-Hogg
- Department of Chemistry, Imperial College London, SW7 2AZ, UK; Institute
of Chemical Biology, Imperial College London, SW72AZ, UK
| | - Naoko Masumoto
- Department of Chemistry, Imperial College London, SW7 2AZ, UK; Institute
of Chemical Biology, Imperial College London, SW72AZ, UK
| | - George Bodakh
- Department of Chemistry, Imperial College London, SW7 2AZ, UK; Institute
of Chemical Biology, Imperial College London, SW72AZ, UK
| | - Antonio D. Konitsiotis
- Molecular Medicine Section, National Heart & Lung Institute, Imperial
College London, London SW7 2AZ, UK
| | - Emmanuelle Thinon
- Department of Chemistry, Imperial College London, SW7 2AZ, UK; Institute
of Chemical Biology, Imperial College London, SW72AZ, UK
| | - Ursula R. Rodgers
- Molecular Medicine Section, National Heart & Lung Institute, Imperial
College London, London SW7 2AZ, UK
| | - Raymond J. Owens
- Oxford Protein Production Facility UK, The Research Complex at Harwell,
Rutherford Appleton Laboratory, Harwell Science & Innovation Centre, Harwell
OX11 0FA, UK
| | - Anthony I. Magee
- Molecular Medicine Section, National Heart & Lung Institute, Imperial
College London, London SW7 2AZ, UK
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, SW7 2AZ, UK; Institute
of Chemical Biology, Imperial College London, SW72AZ, UK
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Lanyon-Hogg T, Masumoto N, Bodakh G, Konitsiotis AD, Thinon E, Rodgers UR, Owens RJ, Magee AI, Tate EW. Click chemistry armed enzyme-linked immunosorbent assay to measure palmitoylation by hedgehog acyltransferase. Anal Biochem 2015; 490:66-72. [PMID: 26334609 PMCID: PMC4615133 DOI: 10.1016/j.ab.2015.08.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 12/30/2022]
Abstract
Hedgehog signaling is critical for correct embryogenesis and tissue development. However, on maturation, signaling is also found to be aberrantly activated in many cancers. Palmitoylation of the secreted signaling protein sonic hedgehog (Shh) by the enzyme hedgehog acyltransferase (Hhat) is required for functional signaling. To quantify this important posttranslational modification, many in vitro Shh palmitoylation assays employ radiolabeled fatty acids, which have limitations in terms of cost and safety. Here we present a click chemistry armed enzyme-linked immunosorbent assay (click-ELISA) for assessment of Hhat activity through acylation of biotinylated Shh peptide with an alkyne-tagged palmitoyl-CoA (coenzyme A) analogue. Click chemistry functionalization of the alkyne tag with azido-FLAG peptide allows analysis through an ELISA protocol and colorimetric readout. This assay format identified the detergent n-dodecyl β-d-maltopyranoside as an improved solubilizing agent for Hhat activity. Quantification of the potency of RU-SKI small molecule Hhat inhibitors by click-ELISA indicated IC50 values in the low- or sub-micromolar range. A stopped assay format was also employed that allows measurement of Hhat kinetic parameters where saturating substrate concentrations exceed the binding capacity of the streptavidin-coated plate. Therefore, click-ELISA represents a nonradioactive method for assessing protein palmitoylation in vitro that is readily expandable to other classes of protein lipidation.
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Affiliation(s)
- Thomas Lanyon-Hogg
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - Naoko Masumoto
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - George Bodakh
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - Antonio D Konitsiotis
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington SW7 2AZ, UK
| | - Emmanuelle Thinon
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - Ursula R Rodgers
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington SW7 2AZ, UK
| | - Raymond J Owens
- Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK; OPPF-UK, The Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell, Oxfordshire, OX11 0FA, UK
| | - Anthony I Magee
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington SW7 2AZ, UK.
| | - Edward W Tate
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK.
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Jakobs P, Exner S, Schürmann S, Pickhinke U, Bandari S, Ortmann C, Kupich S, Schulz P, Hansen U, Seidler DG, Grobe K. Scube2 enhances proteolytic Shh processing from the surface of Shh-producing cells. J Cell Sci 2014; 127:1726-37. [PMID: 24522195 DOI: 10.1242/jcs.137695] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
All morphogens of the Hedgehog (Hh) family are synthesized as dual-lipidated proteins, which results in their firm attachment to the surface of the cell in which they were produced. Thus, Hh release into the extracellular space requires accessory protein activities. We suggested previously that the proteolytic removal of N- and C-terminal lipidated peptides (shedding) could be one such activity. More recently, the secreted glycoprotein Scube2 (signal peptide, cubulin domain, epidermal-growth-factor-like protein 2) was also implicated in the release of Shh from the cell membrane. This activity strictly depended on the CUB domains of Scube2, which derive their name from the complement serine proteases and from bone morphogenetic protein-1/tolloid metalloproteinases (C1r/C1s, Uegf and Bmp1). CUB domains function as regulators of proteolytic activity in these proteins. This suggested that sheddases and Scube2 might cooperate in Shh release. Here, we confirm that sheddases and Scube2 act cooperatively to increase the pool of soluble bioactive Shh, and that Scube2-dependent morphogen release is unequivocally linked to the proteolytic processing of lipidated Shh termini, resulting in truncated soluble Shh. Thus, Scube2 proteins act as protease enhancers in this setting, revealing newly identified Scube2 functions in Hh signaling regulation.
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Affiliation(s)
- Petra Jakobs
- The Institute for Physiological Chemistry and Pathobiochemistry, Westfälische Wilhelms Universität Münster, Waldeyerstrasse 15, D-48149 Münster, Germany
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