RESUMEN
Patients diagnosed with basal-like breast cancer suffer from poor prognosis and limited treatment options. There is an urgent need to identify new targets that can benefit patients with basal-like and claudin-low (BL-CL) breast cancers. We screened fractions from our Marine Invertebrate Compound Library (MICL) to identify compounds that specifically target BL-CL breast cancers. We identified a previously unreported trisulfated sterol, i.e., topsentinol L trisulfate (TLT), which exhibited increased efficacy against BL-CL breast cancers relative to luminal/HER2+ breast cancer. Biochemical investigation of the effects of TLT on BL-CL cell lines revealed its ability to inhibit activation of AMP-activated protein kinase (AMPK) and checkpoint kinase 1 (CHK1) and to promote activation of p38. The importance of targeting AMPK and CHK1 in BL-CL cell lines was validated by treating a panel of breast cancer cell lines with known small molecule inhibitors of AMPK (dorsomorphin) and CHK1 (Ly2603618) and recording the increased effectiveness against BL-CL breast cancers as compared with luminal/HER2+ breast cancer. Finally, we generated a drug response gene-expression signature and projected it against a human tumor panel of 12 different cancer types to identify other cancer types sensitive to the compound. The TLT sensitivity gene-expression signature identified breast and bladder cancer as the most sensitive to TLT, while glioblastoma multiforme was the least sensitive.
Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Esteroles/farmacología , Proteínas Quinasas Activadas por AMP/efectos de los fármacos , Proteínas Quinasas Activadas por AMP/metabolismo , Antineoplásicos/química , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/efectos de los fármacos , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/metabolismo , Claudinas/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Esteroles/química , Proteínas Quinasas p38 Activadas por Mitógenos/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Chemistry drives many biological interactions between the microbiota and host animals, yet it is often challenging to identify the chemicals involved. This poses a problem, as such small molecules are excellent sources of potential pharmaceuticals, pretested by nature for animal compatibility. We discovered anti-HIV compounds from small, marine tunicates from the Eastern Fields of Papua New Guinea. Tunicates are a reservoir for new bioactive chemicals, yet their small size often impedes identification or even detection of the chemicals within. We solved this problem by combining chemistry, metagenomics, and synthetic biology to directly identify and synthesize the natural products. We show that these anti-HIV compounds, the divamides, are a novel family of lanthipeptides produced by symbiotic bacteria living in the tunicate. Neighboring animal colonies contain structurally related divamides that differ starkly in their biological properties, suggesting a role for biosynthetic plasticity in a native context wherein biological interactions take place.
Asunto(s)
Fármacos Anti-VIH/farmacología , Productos Biológicos/farmacología , Descubrimiento de Drogas , Infecciones por VIH/tratamiento farmacológico , Microbiota , Simbiosis , Animales , Bacterias , ADN/análisis , Evaluación Preclínica de Medicamentos , Genómica , Humanos , Lisinoalanina/química , Metagenoma , Metagenómica , Familia de Multigenes , Péptidos/farmacología , Relación Estructura-Actividad , Biología Sintética , Linfocitos T/efectos de los fármacos , UrocordadosRESUMEN
The presence of latent HIV-1 in infected individuals represents a major barrier preventing viral eradication. For that reason, reactivation of latent viruses in the presence of antiretroviral regimens has been proposed as a therapeutic strategy to achieve remission. We screened for small molecules and identified several benzotriazole derivatives with the ability to reactivate latent HIV-1. In the presence of IL-2, benzotriazoles reactivated and reduced the latent reservoir in primary cells, and, remarkably, viral reactivation was achieved without inducing cell proliferation, T cell activation, or cytokine release. Mechanistic studies showed that benzotriazoles block SUMOylation of phosphorylated STAT5, increasing STAT5's activity and occupancy of the HIV-1 LTR. Our results identify benzotriazoles as latency reversing agents and STAT5 signaling and SUMOylation as targets for HIV-1 eradication strategies. These compounds represent a different direction in the search for "shock and kill" therapies.
Asunto(s)
Infecciones por VIH/metabolismo , VIH-1/efectos de los fármacos , Factor de Transcripción STAT5/metabolismo , Sumoilación/efectos de los fármacos , Triazoles/farmacología , Activación Viral/efectos de los fármacos , Latencia del Virus/efectos de los fármacos , Adolescente , Proliferación Celular/efectos de los fármacos , Infecciones por VIH/virología , Humanos , Interleucina-2/metabolismo , Activación de Linfocitos/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Linfocitos T/efectos de los fármacos , Linfocitos T/metabolismoRESUMEN
The synthesis of dehaloperophoramidine, a non-halogenated derivative of the marine natural product perophoramidine, and its biological activity towards HCT116, HT29 and LoVo colorectal carcinoma cells is reported. A [3,3]-Claisen rearrangement and an epoxide opening/allylsilylation reaction installed the contiguous all-carbon quaternary stereocentres with the required relative stereochemistry.
RESUMEN
A library consisting of characterized marine natural products as well as synthetic derivatives was screened for compounds capable of inhibiting the production of hydrogen sulfide (H2S) by cystathionine beta-synthase (CBS). Eight hits were validated and shown to inhibit CBS activity with IC50 values ranging from 83 to 187µM. The majority of hits came from a series of synthetic polyandrocarpamine derivatives. In addition, a modified fluorogenic probe for H2S detection with improved solubility in aqueous solutions is reported.
Asunto(s)
Aminas/química , Cistationina betasintasa/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Sulfuro de Hidrógeno/metabolismo , Imidazoles/química , Urocordados/química , Aminas/aislamiento & purificación , Aminas/farmacología , Animales , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Productos Biológicos/farmacología , Cistationina betasintasa/metabolismo , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Humanos , Sulfuro de Hidrógeno/análisis , Imidazoles/aislamiento & purificación , Imidazoles/farmacologíaRESUMEN
An antimalarial screen for plants collected from Papua New Guinea identified an extract of Horsfieldia spicata as having activity. Isolation of the active constituents led to the identification of two new compounds: myristicyclins A (1) and B (2). Both compounds are procyanidin-like congeners of myristinins lacking a pendant aromatic ring. Myristicyclin A was found to inhibit the ring, trophozoite, and schizont stages of Plasmodium falciparum at similar concentrations in the mid-µM range.
Asunto(s)
Antimaláricos/aislamiento & purificación , Antimaláricos/farmacología , Biflavonoides/aislamiento & purificación , Biflavonoides/farmacología , Catequina/aislamiento & purificación , Catequina/farmacología , Plasmodium falciparum/efectos de los fármacos , Proantocianidinas/aislamiento & purificación , Proantocianidinas/farmacología , Antimaláricos/química , Biflavonoides/química , Catequina/química , Malaria Falciparum/tratamiento farmacológico , Estructura Molecular , Papúa Nueva Guinea , Plasmodium falciparum/crecimiento & desarrollo , Proantocianidinas/química , EstereoisomerismoRESUMEN
By means of bioassay-guided fractionation, a new steroidal alkaloid, plakinamine M (1), and the known compound, plakinamine L (2), with a unique acyclic side chain, were isolated from the marine sponge Corticium sp. collected from New Britain, Papua New Guinea. The structures were determined on the basis of extensive 1D and 2D NMR and HRESIMS. The two compounds showed inhibition of Mycobacterium tuberculosis with MIC values of 15.8 and 3.6 µg/mL, respectively.
Asunto(s)
Alcaloides/aislamiento & purificación , Mycobacterium tuberculosis/efectos de los fármacos , Poríferos/química , Esteroides/aislamiento & purificación , Alcaloides/química , Alcaloides/farmacología , Animales , Ensayos de Selección de Medicamentos Antitumorales , Biología Marina , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Papúa Nueva Guinea , Esteroides/química , Esteroides/farmacología , Reino UnidoRESUMEN
Two merotriterpenoid hydroquinone sulfates designated adociasulfate-13 (1) and adociasulfate-14 (2) were purified from Cladocroce aculeata (Chalinidae) along with adociasulfate-8. All three compounds were found to inhibit microtubule-stimulated ATPase activity of kinesin at 15 µM by blocking both the binding of microtubules and the processive motion of kinesin along microtubules. These findings directly show that substitution of the 5'-sulfate in 1 for a glycolic acid moiety in 2 maintains kinesin inhibition. Nomarski imaging and bead diffusion assays in the presence of adociasulfates showed no signs of either free-floating or bead-bound adociasulfate aggregates. Single-molecule biophysical experiments also suggest that inhibition of kinesin activity does not involve adociasulfate aggregation. Furthermore, both mitotic and nonmitotic kinesins are inhibited by adociasulfates to a significantly different extent. We also report evidence that microtubule binding of nonkinesin microtubule binding domains may be affected by adociasulfates.
Asunto(s)
Descubrimiento de Drogas/tendencias , Hidroquinonas/farmacología , Cinesinas/antagonistas & inhibidores , Poríferos/química , Ésteres del Ácido Sulfúrico/farmacología , Triterpenos/farmacología , Animales , Biofisica , Permeabilidad de la Membrana Celular/fisiología , Descubrimiento de Drogas/métodos , Humanos , Hidroquinonas/metabolismo , Estructura Molecular , Unión Proteica , Espectrofotometría , Ésteres del Ácido Sulfúrico/metabolismo , Triterpenos/metabolismoRESUMEN
A major hurdle in using complex systems for drug screening is the difficulty of defining the mechanistic targets of small molecules. The zebrafish provides an excellent model system for juxtaposing developmental phenotypes with mechanism discovery using organism genetics. We carried out a phenotype-based screen of uncharacterized small molecules in zebrafish that produced a variety of chemically induced phenotypes with potential genetic parallels. Specifically, kalihinol F caused an undulated notochord, defects in pigment formation, hematopoiesis, and neural development. These phenotypes were strikingly similar to the zebrafish mutant, calamity, an established model of copper deficiency. Further studies into the mechanism of action of kalihinol F revealed a copper-chelating activity. Our data support this mechanism of action for kalihinol F and the utility of zebrafish as an effective system for identifying therapeutic and target pathways.
Asunto(s)
Quelantes/química , Cobre/química , Diterpenos/química , Nitrilos/química , Animales , Supervivencia Celular/efectos de los fármacos , Quelantes/toxicidad , Cobre/farmacología , Diterpenos/toxicidad , Embrión no Mamífero/efectos de los fármacos , Embrión no Mamífero/metabolismo , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Células Hep G2 , Humanos , Mutación , Nitrilos/toxicidad , Notocorda/efectos de los fármacos , Notocorda/metabolismo , Fenotipo , Pez Cebra/metabolismoRESUMEN
Over the past 30 years, approximately 140 papers have been published on marine natural products chemistry and related research from the Fiji Islands. These came about from studies starting in the early 1980s by the research groups of Crews at the University of California Santa Cruz, Ireland at the University of Utah, Gerwick from the Scripps Institution of Oceanography, the University of California at San Diego and the more recent groups of Hay at the Georgia Institute of Technology (GIT) and Jaspars from the University of Aberdeen. This review covers both known and novel marine-derived natural products and their biological activities. The marine organisms reviewed include invertebrates, plants and microorganisms, highlighting the vast structural diversity of compounds isolated from these organisms. Increasingly during this period, natural products chemists at the University of the South Pacific have been partners in this research, leading in 2006 to the development of a Centre for Drug Discovery and Conservation (CDDC).
Asunto(s)
Productos Biológicos , Biología Marina , Animales , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Productos Biológicos/farmacología , Fiji , Hongos/química , Humanos , Invertebrados/química , Estructura Molecular , Plantas Medicinales/química , Poríferos/química , Urocordados/químicaRESUMEN
As part of our screening for anti-HIV agents from marine invertebrates, the MeOH extract of Didemnum molle was tested and showed moderate in vitro anti-HIV activity. Bioassay-guided fractionation of a large-scale extract allowed the identification of two new cyclopeptides, mollamides E and F (1 and 2), and one new tris-phenethyl urea, molleurea A (3). The absolute configurations were established using the advanced Marfey's method. The three compounds were evaluated for anti-HIV activity in both an HIV integrase inhibition assay and a cytoprotective cell-based assay. Compound 2 was active in both assays with IC(50) values of 39 and 78 µM, respectively. Compound 3 was active only in the cytoprotective cell-based assay, with an IC(50) value of 60 µM.
Asunto(s)
Inhibidores de Integrasa VIH/aislamiento & purificación , Inhibidores de Integrasa VIH/farmacología , Péptidos Cíclicos/aislamiento & purificación , Péptidos Cíclicos/farmacología , Compuestos de Fenilurea/aislamiento & purificación , Compuestos de Fenilurea/farmacología , Tiazolidinas/aislamiento & purificación , Tiazolidinas/farmacología , Urocordados/química , Animales , Inhibidores de Integrasa VIH/química , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Papúa Nueva Guinea , Péptidos Cíclicos/química , Compuestos de Fenilurea/química , Tiazolidinas/químicaRESUMEN
Four new tetromycin derivatives, tetromycins 1-4 and a previously known one, tetromycin B (5) were isolated from Streptomyces axinellae Pol001(T) cultivated from the Mediterranean sponge Axinella polypoides. Structures were assigned using extensive 1D and 2D NMR spectroscopy as well as HRESIMS analysis. The compounds were tested for antiparasitic activities against Leishmania major and Trypanosoma brucei, and for protease inhibition against several cysteine proteases such as falcipain, rhodesain, cathepsin L, cathepsin B, and viral proteases SARS-CoV M(pro), and PL(pro). The compounds showed antiparasitic activities against T. brucei and time-dependent inhibition of cathepsin L-like proteases with K(i) values in the low micromolar range.
Asunto(s)
Compuestos Heterocíclicos de 4 o más Anillos/aislamiento & purificación , Inhibidores de Proteasas/aislamiento & purificación , Tripanocidas/aislamiento & purificación , Animales , Antiprotozoarios/aislamiento & purificación , Antiprotozoarios/farmacología , Axinella/microbiología , Catepsina B/antagonistas & inhibidores , Catepsina L/antagonistas & inhibidores , Proteasas 3C de Coronavirus , Cisteína Endopeptidasas/efectos de los fármacos , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Leishmania major/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Inhibidores de Proteasas/farmacología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/efectos de los fármacos , Streptomyces/química , Tripanocidas/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Proteínas Virales/antagonistas & inhibidoresRESUMEN
Green plant-origin electrophilic compounds are a newly-recognized class of neuroprotective compounds that provide neuroprotection through activation of the Nrf2/ARE pathway. Electrophilic hydroquinones are of particular interest due to their ability to become electrophilic quinones upon auto-oxidation. Although marine organisms frequently produce a variety of electrophilic compounds, the detailed mechanisms of action of these compounds remain unknown. Here, we focused on the neuroprotective effects of strongylophorine-8 (STR8), a para-hydroquinone-type pro-electrophilic compound from the sponge Petrosia (Strongylophora) corticata. STR8 activated the Nrf2/ARE pathway, induced phase 2 enzymes, and increased glutathione, thus protecting neuronal cells from oxidative stress. Microarray analysis indicated that STR8 induced a large number of phase 2 genes, the regulation of which is controlled by the Nrf2/ARE pathway. STR8 is the first example of a neuroprotective pro-electrophilic compound from marine organisms.
Asunto(s)
Factor 2 Relacionado con NF-E2/metabolismo , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Petrosia/química , Animales , Antioxidantes/farmacología , Línea Celular , Humanos , Neuronas/metabolismo , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/aislamiento & purificación , Elementos de Respuesta/efectos de los fármacosRESUMEN
Fibrosterol sulfate A is a polysulfated bis-steroid with an atypical side chain. Due to the flexibility of the linker, large-scale motions that change dramatically the shape of the entire molecule are expected. Such motions pose major challenges to the structure elucidation and the correct determination of configuration. In this study, we will describe the determination of the relative configuration of fibrosterol sulfate A through a residual dipolar coupling based multiple alignment tensor analysis complemented by molecular dynamics. For completeness, we applied also the single tensor approach which is unreliable due to the large-scale motions and compare the results.
Asunto(s)
Simulación de Dinámica Molecular , Esteroles/química , Espectroscopía de Resonancia Magnética , Conformación Molecular , Movimiento (Física)RESUMEN
A new fascaplysin analogue, 3-bromohomofascaplysin A (1), along with two known analogues, homofascaplysin A (2) and fascaplysin (3), were isolated from a Fijian Didemnum sp. ascidian. The absolute configurations of 3-bromohomofascaplysin A (1) and homofascaplysin A (2) were determined via experimental and theoretically calculated ECD spectra. The differential activities of 1-3 against different blood-borne life stages of the malaria pathogen Plasmodium falciparum were assessed. Homofascaplysin A (2) displayed an IC(50) of 0.55±0.11 nM against ring stage parasites and 105±38 nM against all live parasites. Given the stronger resistance of ring stage parasites against most current antimalarials relative to the other blood stages, homofascaplysin A (2) represents a promising agent for treatment of drug resistant malaria.
Asunto(s)
Indoles/química , Urocordados/química , Animales , Antimaláricos/química , Antimaláricos/aislamiento & purificación , Antimaláricos/farmacología , Hidrocarburos Bromados/química , Hidrocarburos Bromados/aislamiento & purificación , Indoles/aislamiento & purificación , Indoles/farmacología , Conformación Molecular , Resonancia Magnética Nuclear Biomolecular , Plasmodium falciparum/efectos de los fármacosRESUMEN
Four new tris-bromoindole cyclic guanidine alkaloids, araiosamines A-D, were isolated from the methanol extract of a marine sponge, Clathria (Thalysias) araiosa, collected from Vanuatu. Their carbon skeletons delineate a new class of indole alkaloids apparently derived from a linear polymerization process involving a carbon-carbon bond formation. Comparison of the structures including the relative configurations suggests a common intermediate containing a dihydroaminopyrimidine moiety capable of undergoing various modalities of conjugate addition to yield unprecedented ring systems.
Asunto(s)
Alcaloides/química , Guanidinas/química , Guanidinas/aislamiento & purificación , Poríferos/química , Alcaloides/aislamiento & purificación , Animales , Espectroscopía de Resonancia Magnética/normas , Modelos Moleculares , Estructura Molecular , Estándares de Referencia , EstereoisomerismoRESUMEN
Four new depsipeptides, mirabamides E-H (1-4), and the known depsipeptide mirabamide C (5) have been isolated from the sponge Stelletta clavosa, collected from the Torres Strait. The planar structures were determined on the basis of extensive 1D and 2D NMR and HRESIMS. The absolute configurations were established by the advanced Marfey's method, NMR, and GC-MS. The four new compounds all showed strong inhibition of HIV-1 in a neutralization assay with IC(50) values of 121, 62, 68, and 41 nM, respectively.
Asunto(s)
Fármacos Anti-VIH/aislamiento & purificación , Fármacos Anti-VIH/farmacología , Depsipéptidos/aislamiento & purificación , Depsipéptidos/farmacología , Poríferos/química , Animales , Fármacos Anti-VIH/química , Depsipéptidos/química , VIH-1/efectos de los fármacos , Concentración 50 Inhibidora , Estructura Molecular , Resonancia Magnética Nuclear BiomolecularRESUMEN
To understand better the endogenous sources of MHC class I peptide ligands, we generated an antigenic reporter protein whose degradation is rapidly and reversibly controlled with Shield-1, a cell-permeant drug. Using this system, we demonstrate that defective ribosomal products (DRiPs) represent a major and highly efficient source of peptides and are completely resistant to our attempts to stabilize the protein. Although peptides also derive from nascent Shield-1-sensitive proteins and "retirees" created by Shield-1 withdrawal, these are much less efficient sources on a molar basis. We use this system to identify two drugs--each known to inhibit polyubiquitin chain disassembly--that selectively inhibit presentation of Shield-1-resistant DRiPs. These findings provide the initial evidence for distinct biochemical pathways for presentation of DRiPs versus retirees and implicate polyubiquitin chain disassembly or the actions of deubiquitylating enzymes as playing an important role in DRiP presentation.
Asunto(s)
Presentación de Antígeno/inmunología , Linfocitos T CD8-positivos/inmunología , Vigilancia Inmunológica , Biosíntesis de Péptidos/inmunología , Proteínas Ribosómicas/biosíntesis , Proteínas Ribosómicas/deficiencia , Transducción de Señal/inmunología , Animales , Presentación de Antígeno/efectos de los fármacos , Presentación de Antígeno/genética , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/metabolismo , Línea Celular Tumoral , Permeabilidad de la Membrana Celular/efectos de los fármacos , Permeabilidad de la Membrana Celular/genética , Permeabilidad de la Membrana Celular/inmunología , Femenino , Proteínas Fluorescentes Verdes/biosíntesis , Proteínas Fluorescentes Verdes/genética , Antígenos H-2/biosíntesis , Antígenos H-2/genética , Vigilancia Inmunológica/efectos de los fármacos , Vigilancia Inmunológica/genética , Ratones , Ratones Endogámicos C57BL , Morfolinas/farmacología , Ovalbúmina/inmunología , Ovalbúmina/metabolismo , Biosíntesis de Péptidos/efectos de los fármacos , Biosíntesis de Péptidos/genética , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismo , Estabilidad Proteica/efectos de los fármacos , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Ribosómicas/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genéticaRESUMEN
Two ring-A-aromatized bile acids, 1 and 2, were isolated from the sponge Sollasella moretonensis, collected from the seabed of northern Queensland. Structures were assigned on the basis of extensive 1D and 2D NMR studies, as well as analysis by HRESIMS. Compound 2 has previously been produced synthetically, though this marks its first isolation from a natural source.
Asunto(s)
Ácidos y Sales Biliares/aislamiento & purificación , Colenos/aislamiento & purificación , Poríferos/química , Animales , Ácidos y Sales Biliares/química , Noresteroides/aislamiento & purificaciónRESUMEN
Wnt proteins are secreted post-translationally modified proteins that signal locally to regulate development and proliferation. The production of bioactive Wnts requires a number of dedicated factors in the secreting cell whose coordinated functions are not fully understood. A screen for small molecules identified inhibitors of vacuolar acidification as potent inhibitors of Wnt secretion. Inhibition of the V-ATPase or disruption of vacuolar pH gradients by diverse drugs potently inhibited Wnt/ß-catenin signaling both in cultured human cells and in vivo, and impaired Wnt-regulated convergent extension movements in Xenopus embryos. WNT secretion requires its binding to the carrier protein wntless (WLS); we find that WLS is ER-resident in human cells and WNT3A binding to WLS requires PORCN-dependent lipid modification of WNT3A at serine 209. Inhibition of vacuolar acidification results in accumulation of the WNT3A-WLS complex both in cells and at the plasma membrane. Modeling predictions suggest that WLS has a lipid-binding ß-barrel that is similar to the lipocalin-family fold. We propose that WLS binds Wnts in part through a lipid-binding domain, and that vacuolar acidification is required to release palmitoylated WNT3A from WLS in secretory vesicles, possibly to facilitate transfer of WNT3A to a soluble carrier protein.