Stromal Cell-derived Factor 2 Research Articles

Arabidopsis ERdj3B coordinates with ERECTA-family receptor kinases to regulate ovule development and the heat stress response.

The endoplasmic reticulum-localized DnaJ family 3B (ERdj3B), is a component of the stromal cell-derived factor 2 (SDF2)-ERdj3B-binding immunoglobulin protein (BiP) chaperone complex, which functions in protein folding, translocation, and quality control. We found that ERdj3B mutations affected integument development in the Ler ecotype but not in the Col-0 ecotype of Arabidopsis (Arabidopsis thaliana). Map-based cloning identified the ERECTA (ER) gene as a natural modifier of ERdj3B. The double mutation of ERdj3B and ER caused a major defect in the inner integument under heat stress. Additional mutation of the ER paralog ERECTA-LIKE 1 (ERL1) or ERL2 to the erdj3b er double mutant exacerbated the defective integument phenotype. The double mutation of ER and SDF2, the other component of the SDF2-ERdj3B-BiP complex, resulted in similar defects in the inner integument. Furthermore, both the protein abundance and plasma membrane partitioning of ER, ERL1, and ERL2 were markedly reduced in erdj3b plants, indicating that the SDF2-ERdj3B-BiP chaperone complex might control the translocation of ERECTA-family proteins from the endoplasmic reticulum to the plasma membrane. Our results suggest that the SDF2-ERdj3B-BiP complex functions in ovule development and the heat stress response in coordination with ERECTA-family receptor kinases.

Potato virus X-mediated constitutive expression of Plutella xylostella PxSDF2L1 gene in Nicotiana benthamiana confers resistance to Phytophthora parasitica var. nicotianae

BackgroundThe Plutella xylostella PxSDF2L1 gene was previously reported to enhance insect resistance to pathogen at high basal transcription rate. PxSDF2L1 shows similitude with the stromal cell-derived factor 2 (SDF2), an ER stress-induced chaperon protein that is highly conserved throughout animals and plants. The precise biological function of SDF2 is not clear, but its expression is required for innate immunity in plants. Here, we investigate whether a continuous expression of PxSDF2L1 in Nicotiana benthamiana can similarly confer resistance to plant pathogen, particularly, the black shank Phytophthora parasitica var. nicotianae.ResultsThe N. benthamiana plants were inoculated with agrobacteria transformed with a PVX-based binary vector carrying the PxSDF2L1 gene; similar agroinoculation experiments with a PVX vector carrying the GFP gene were used for controls. In pot trials, agroinfected N. benthamiana plants constitutively expressing PxSDF2L1 showed a significant reduction of stem disease symptoms caused by the inoculation with P. parasitica, compared with controls.ConclusionsWe confirm a role of PxSDF2L1 in resistance to black shank, with a potential application to engineering active resistance against this oomycete in the commercial N. tabacum species and propose its evaluation in other crop families and plant pathogens.

Stromal Cell-Derived Factor (SDF) 2 and the Endoplasmic Reticulum Stress Response of Trophoblast Cells in Gestational Diabetes Mellitus and In vitro Hyperglycaemic Condition.

The endoplasmic reticulum (ER) stress response and the unfolded protein response (UPR) are essential cellular mechanisms to ensure the proper functioning of ER in adverse conditions. However, activation of these pathways has also been associated with insulin resistance and cell death in pathological conditions such as diabetes mellitus. In the present study, we investigated whether stromal cell-derived factor 2 (SDF2)-an ER stress-responsive factor-is related to ER response in placental cells exposed to maternal gestational diabetes mellitus (GDM) or to a hyperglycaemic in vitro condition. The study aimed to investigate the role of SDF2 in BeWo cells , a trophoblast cell line originating from choriocarcinoma , and in placental tissue under hyperglycaemic conditions. Protein levels of SDF2 and UPR factors, glucose-related protein 78 (GRP78) and eukaryotic initiation factor 2 alpha (elF2 alpha) were evaluated in the placentae of pregnant women diagnosed with GDM and treated by diet-control (insulin was added when necessary). The mRNA expression of SDF2 and UPR factors CHOP and sXBP1 were assessed in cultured BeWo cells challenged with glucose and treated with or without insulin. SDF2 expression was increased in the placentae of GDM women treated with diet. However, its values were similar to those of normoglycemic controls when the GDM women were treated with insulin and diet. BeWo cells cultured with high glucose and insulin showed decreased SDF2 expression, while high glucose increased CHOP and sXBP1 expression, which was then significantly reverted with insulin treatment. Our findings extend the understanding of ER stress and SDF2 expression in placentae exposed to hyperglycaemia, highlighting the relevance of insulin in reducing the levels of ER stress factors in placental cells. Understanding the effect of ER stress partners such as SDF2 on signalling pathways involved in gestation, complicated by hyperglycaemia, is pivotal for basic biomedical research and may lead to new therapeutic possibilities.

Generation of Rat Monoclonal Antibodies Specific for Human Stromal Cell-Derived Factor-2.

Stromal cell-derived factor-2 (SDF-2) is reportedly involved in multiple endoplasmic reticulum (ER) functions, including the misfolded protein catabolic process, protein glycosylation, and ER protein quality control. However, the precise molecular and cellular functions of SDF-2 remain unknown. Previously, we discovered that SDF-2 mediates acquired resistance to oxaliplatin in human gastric cancer cells. In this study, we have generated SDF-2-specific monoclonal antibodies (mAbs), using the rat medial iliac lymph node method, as a tool to explore novel mechanisms of oxaliplatin resistance. The antibodies detected endogenous human SDF-2 in immunoblotting analyses. In addition, immunoprecipitation analyses revealed the availability of these antibodies for human SDF-2. Thus, these mAbs will be available to elucidate molecular and cellular functions of SDF-2 in cancer cells.

Monoclonal Antibody Against Stromal Cell-Derived Factor 2.

Monoclonal Antibodies in Immunodiagnosis and ImmunotherapyVol. 39, No. 1 Monoclonal AntibodiesOpen AccessCreative Commons licenseMonoclonal Antibody Against Stromal Cell-Derived Factor 2Published Online:14 Feb 2020https://doi.org/10.1089/mab.2019.0046AboutSectionsPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail Antigen Used for ImmunizationA synthetic peptide of 20 amino acids (GIFMKPSELLKAEAHHAELC), which corresponded to residues 193–211 of human stromal cell-derived factor 2 (SDF-2).Method of ImmunizationThe rat lymph node method established by Sado et al.(2)Parental Cell Line Used for FusionMouse myeloma SP2 cells.Selection and Cloning ProcedureThe hybridoma supernatants were screened using an enzyme linked immunosorbent assay (ELISA) against the human SDF-2 synthetic peptide. Positive clones were subcloned and rescreened by ELISA, immunoblotting, and immunoprecipitation.Heavy and Light Chains of ImmunoglobulinRat IgG2ακ.SpecificityWe determined specificity of MAb by immunoblotting analysis using the microsomes of SDF-2-knockout OCUM-2M/OXA cells. Our MAb gave specific signals as a 23 kDa band in the wild-type cells only.Specific Antigen IdentifiedWe did not identify specific antigen. However, it would include 20 amino acids (GIFMKPSELLKAEAHHAELC), which corresponded to residues 193–211 of human SDF-2.Availability YesNoTissue culture supernatant[ ][✓]Ascitic fluid[ ][✓]Hybridoma cells[✓][ ]

SDF2-like protein 1 (SDF2L1) regulates the endoplasmic reticulum localization and chaperone activity of ERdj3 protein

Molecular chaperones facilitate protein folding by associating with nascent polypeptides, thereby preventing protein misfolding and aggregation. Endoplasmic reticulum (ER) chaperone BiP, the sole HSP70 chaperone in the ER, is regulated by HSP40 chaperones, including ER-resident protein ERdj3 (DNAJB11). ERdj3 lacks an ER retrieval signal, is secreted under ER stress conditions, and functions as a chaperone in the extracellular space, but how its secretion is regulated remains unclear. We recently showed that ERdj3 forms a complex with ER-resident stromal cell-derived factor 2 (SDF2) and SDF2L1 (SDF2-like protein 1) and thereby prevents protein aggregation during the BiP chaperone cycle. However, the contribution of the ERdj3-SDF2L1 complex to protein quality control is poorly understood. Here, we analyzed the intracellular localization and chaperone activity of ERdj3 in complex with SDF2L1. We found that ERdj3 was retained in the ER by associating with SDF2/SDF2L1. In vitro analyses revealed that the ERdj3 dimer incorporated two SDF2L1 molecules; otherwise, ERdj3 alone formed a homotetramer. The ERdj3-SDF2L1 complex suppressed ER protein aggregation, and this suppression did not require substrate transfer to BiP. The ERdj3-SDF2L1 complex inhibited aggregation of denatured GSH S-transferase (GST) in vitro and maintained GST in a soluble oligomeric state. Both in cellulo and in vitro, the chaperone activities of the ERdj3-SDF2L1 complex were higher than those of ERdj3 alone. These findings suggest that, under normal conditions, ERdj3 functions as an ER chaperone in complex with SDF2/SDF2L1 but is secreted into the extracellular space when it cannot form this complex.

The role of SDF2 (Stromal cell derived factor-2) in gestational diseases through PERK- branch of the Unfolded Protein Response/ER stress.

Tripterygium hypoglaucum (Levl.) Hutch (THH) is the source plant of a traditional Chinese medicine named Kunmingshanhaitang, which was first recorded in Compendium of Materia Medica. Like Tripterygium wilfordii Hook f. (TWH), THH is also widely used in the treatment of various autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis and psoriasis. The therapeutic effect of THH is closely related to its special compound composition. By now, about 300 compounds have been isolated and identified from THH, including sesquiterpenoids, diterpenoids, triterpenoids, flavonoids, lignans, alkaloids, fatty acids, steroids and others. Further studies found that many compounds originated from THH showed a wide range of biological activities, such as immunosuppression, anti-inflammatory, antitumor, neuroprotection and the others. It is worth noting that THH belongs to the toxic traditional Chinese medicine, commonly known as gut-break grass. Although there have been a lot of studies on the toxic doses of some extracts or isolated compounds of THH, their mechanism remains unclear. Further study on the structure and function relationship of each active and/or toxic compound, analysis of their unique mechanism of action or toxicity mechanism, and exploration of its detoxification methods and new clinical uses will contribute to its better use for human health. In order to better explore the pharmaceutical potential of THH, this paper systematically reviewed its traditional uses, botany, phytochemistry, pharmacology, pharmacokinetics, toxicology and detoxification, which is convenient for further understanding and research.

The role of SDF2 (Stromal cell derived factor 2) in Cell Survival/Death Decision during Endoplasmic Reticulum Stress in Human Trophoblast cells

Mitogen-activated protein kinase (MAPK) cascades play important roles in regulating plant growth, development and stress responses. Here, we report that ZmMKK10, a maize MAP kinase kinase, positively regulates cell death. Sequence comparison to Arabidopsis MKKs has led to ZmMKK10 being classified as a group D MKK. Kinase activity analysis of recombinant ZmMKK10 showed that the Mg2+ ion was required for its kinase activity. Transient expression of ZmMKK10WT or ZmMKK10DD (the active form of ZmMKK10) in maize mesophyll protoplast significantly increased the cell death rate. Inducible expression of ZmMKK10WT or ZmMKK10DD in Arabidopsis transgenic plants caused rapid HR-like cell death, whereas induction of ZmMKK10KR (the inactive form of ZmMKK10) expression in transgenic plants did not yield the same phenotype. Genetic and pharmacological analysis revealed that ZmMKK10-induced cell death in transgenic plants requires the activation of Arabidopsis MPK3 and MPK6 and that it partially depended on ethylene biosynthesis. ZmMPK3 and ZmMPK7, the orthologues of Arabidopsis MPK3 and MPK6, interacted with ZmMKK10 in yeast and ZmMKK10 phosphorylated them both in vitro. Our results demonstrate that ZmMKK10 induces cell death in an ethylene-dependent manner. Furthermore, ZmMPK3 and ZmMPK7 may be the downstream MAPKs in this process.

Protection of stromal cell-derived factor 2 by heat shock protein 72 prevents oxaliplatin-induced cell death in oxaliplatin-resistant human gastric cancer cells

Heat shock protein 72 (Hsp72) is a molecular chaperone that assists in the folding of nascent polypeptides and in the refolding of denatured proteins. In many cancers, Hsp72 is constitutively expressed at elevated levels, which can result in enhanced stress tolerance. Similarly, following treatment with anticancer drugs, Hsp72 binds to denatured proteins that may be essential for survival. We therefore hypothesized that Hsp72 client proteins may play a crucial role in drug resistance. Here, we aimed to identify proteins that are critical for oxaliplatin (OXA) resistance by analyzing human gastric cancer cell lines, as well as OXA-resistant cells via a mass spectrometry-based proteomic approach combined with affinity purification using anti-Hsp72 antibodies. Stromal cell-derived factor 2 (SDF-2) was identified as an Hsp72 client protein unique to OCUM-2M/OXA cells. SDF-2 was overexpressed in OXA-resistant cells and SDF-2 silencing promoted the apoptotic effects of OXA. Furthermore, Hsp72 prevented SDF-2 degradation in a chaperone activity-dependent manner. Together, our data demonstrate that Hsp72 protected SDF-2 to avoid OXA-induced cell death. We propose that inhibition of SDF-2 may comprise a novel therapeutic strategy to counteract OXA-resistant cancers.

Stromal cell-derived factor 2 is critical for Hsp90-dependent eNOS activation.

Endothelial nitric oxide synthase (eNOS) catalyzes the conversion of l-arginine and molecular oxygen into l-citrulline and nitric oxide (NO), a gaseous second messenger that influences cardiovascular physiology and disease. Several mechanisms regulate eNOS activity and function, including phosphorylation at Ser and Thr residues and protein-protein interactions. Combining a tandem affinity purification approach and mass spectrometry, we identified stromal cell-derived factor 2 (SDF2) as a component of the eNOS macromolecular complex in endothelial cells. SDF2 knockdown impaired agonist-stimulated NO synthesis and decreased the phosphorylation of eNOS at Ser(1177), a key event required for maximal activation of eNOS. Conversely, SDF2 overexpression dose-dependently increased NO synthesis through a mechanism involving Akt and calcium (induced with ionomycin), which increased the phosphorylation of Ser(1177) in eNOS. NO synthesis by iNOS (inducible NOS) and nNOS (neuronal NOS) was also enhanced upon SDF2 overexpression. We found that SDF2 was a client protein of the chaperone protein Hsp90, interacting preferentially with the M domain of Hsp90, which is the same domain that binds to eNOS. In endothelial cells exposed to vascular endothelial growth factor (VEGF), SDF2 was required for the binding of Hsp90 and calmodulin to eNOS, resulting in eNOS phosphorylation and activation. Thus, our data describe a function for SDF2 as a component of the Hsp90-eNOS complex that is critical for signal transduction in endothelial cells.

The role of stromal cell derived factor 2 (SDF2) in cell survival/apoptosis decision in trophoblast cells

The role of stromal cell derived factor 2 (SDF2) in cell survival/apoptosis decision in trophoblast cells

Stromal cell derived factor-2 is involved in the unfolded protein response in human placenta

s / Placenta 35 (2014) A1eA112 A104 Objective: Depending on the receptor context the wingless ligand Wnt5a affects non-canonical as well as canonical Wnt signaling thereby controlling different developmental processes. The presence of Wnt5a in decidual stromal cells suggested that the ligand could regulate early placental development and trophoblast behavior. Hence, we herein studied the influence of Wnt5a on trophoblast proliferation and motility. Methods: Immunofluorescence staining and western blot analyses were used to determine Wnt5a-producing cell types in early placental tissues and cell lines. Gene silencing of Wnt5a using siRNAs in SGHPL-5 cells and treatment of placental explant cultures and primary isolated cytotrophoblasts (CTB) with recombinant Wnt5a were performed. Wnt5a-dependent effects on proliferationwere studied by counting cumulative cell numbers, cyclin D1 expression and BrdU incorporation, visualized by immunofluorescence staining. Tomeasure apoptosis, cleaved caspase-3 expressionwas analyzed bywestern blotting. Motility assayswere performed uponWnt5a treatment or gene silencing. Furthermore, Wnt5a dependent activation of signaling pathways was analyzed. Results:Wnt5awas detectable in mesenchymal cells and leucocytes of the villous core and the decidua, as well as in decidual glands, CTBs and the trophoblastic cell line SGHPL-5. Silencing of Wnt5a in SGHPL-5 cells decreased proliferation and cyclin D1 expression which could be reverted by supplementation of recombinant Wnt5a. Additionally, increased BrdU incorporation into villous and cell column trophoblasts of placental explant cultures was detectable upon Wnt5a treatment. Furthermore, knock down cells showed increased apoptosis. Wnt5a addition increased, and gene silencing decreased the motility of SGHPL-5 cells. Treatment of SGHPL-5 cells, CTBs and placental explant cultures with recombinant Wnt5a provoked induction of the MAP Kinase pathway. Conclusions: Expression data and functional studies suggest a major role of the Wnt ligand Wnt5a in maintaining proliferation of CTBs and protection from apoptosis via non canonical Wnt signaling and the MAPK pathway. Supported by grant P-25187 of the Austrian Science Funds (FWF) and Herzfelder'sche Familienstiftung. P2.139-N. STROMAL CELL DERIVED FACTOR-2 IS INVOLVED IN THE UNFOLDED PROTEIN RESPONSE IN HUMAN PLACENTA Aline R. Lorenzon-Ojea , Susan J. Fisher , Estela Bevilacqua a Cell and Developmental Biology University of Sao Paulo, Sao Paulo SP, Brazil; Department of Obstetrics, Gynecology & Reproductive Sciences, School of Medicine University of California San Francisco, San Francisco CA, USA Objetives: Adverse environmental conditions lead to disruption of endoplasmic reticulum homeostasis causing accumulation of unfolded/misfolded proteins in ER and activating the Unfolded Protein Response (UPR). UPR restores ER homeostasis, but if fails, cells go into apoptosis. SDF2 is expressed in humanplacenta; it is upregulated during cytotrophoblast differentiation and downregulated in hypoxia. The human SDF2 is similar to Arabidopsis thaliana SDF2-like protein, which is involved in ER stress response. In this study we investigated the SDF2 role in UPR in human placenta. Methods: Primary cell culture of villous cytotrophoblast and BeWo cells were induced to ER stress with tunicamycin. Protein concentrations of SDF2, GRP78/BiP and Caspase-3 were evaluated by Western Blot. Gene expression of SDF2, sXBP1 and CHOP were investigated through qPCR in SDF2-silenced or not BeWo cells. YWHAZ and b-actin was used as loading control for qPCR and Western Blot respectively. Results: SDF2 is downregulated in CTBs after 3h and 24h of tunicamycin exposure (2.5 and 5.0 mg/mL). In BeWo cells it is downregulated after 6h of treatment and it is restored after 24 h. GRP78/BiP is upregulated after 3h in CTBs, while in BeWo cells is upregulated only after 24 h. sXBP1 and CHOP mRNA confirmed ER stress condition. SDF2 mRNA did not change during tunicamycin treatment. In siRNA assays, CHOP was downregulated and GRP78/BiP activation was antecipated. We did not observed cleaved Caspase 3 for CTBs or BeWo cells. Conclusions: Downregulation of CHOP and antecipation of GRP78/BiP in siRNA treated cells, indicate a role of SDF2 in the control of survival/ apoptosis in trophoblast ER stress response. The placenta faces several changes in environmental conditions during development which could onset the UPR. Identifying new factors and key targets of this response could open a new field of investigation for gestation diseases. *Supported by FAPESP and CNPq P2.140-N. EFFECTS OF THE TRIIODOTHYRONINE IN MOUSE TROPHOBLAST CELLS CULTURE Juneo Silva, Natalia Ocarino, Rogeria Serakides Departamento de Clinica e Cirurgia Veterin arias, Universidade Federal de Minas Gerais, Belo Horizonte/Minas Gerais, Brazil Objectives: The objective of the present study was to evaluate the differentiation and gene expression in vitro of hormonal, immune and angiogenic factors in mouse trophoblast cells with different doses of T3. Methods: Twenty-five adult female mouse were sacrificed at 7,5 days of gestation. Ectoplacental cones were dissected from the maternal tissues and cultured during 24 and 48 hours in standard medium without T3 (control) andwith different doses of T3 (10-4M; 10-7M; 10-9M). The gene expression of Tpbp, Prl3b1, VEGF, PGF, PL-1, and INFy was evaluated in trophoblast cells by real-time RT-PCR. The data were analyzed using an SNK test. Results: The doses of 10-7 and 10-9 M of T3 increased the mRNA expression for Tpbp, PGF, INFy and PL-1 with 24 and/or 48 hours of culture. In addition, the dose of 10-7 M of T3 also increased the gene expression for Pl3b1 and VEGF with 24 hours of culture. The dose of 10-4 M of T3, on the contrary, reduced the mRNA expression for PL-1 and VEGF with 24 and 48 hours of culture, respectively. Conclusion: The doses of 10-7 and 10-9 M of T3 increased the differentiation and gene expression of hormonal, immune and angiogenic factors by mouse trophoblast cells and these effects were dependent of the culture time. In contrast, the dose of 10-4 M of T3 reduced the gene expression of VEGF and PL-1 by trophoblast cells. FUNDING: Fapemig, CNPq, PRPq P2.141-N. MIR-134 REGULATES INVASION AND PROLIFERATION IN HTR-8/SVNEO CELLS Stephanie Ospina-Prieto, Diana M. Morales-Prieto, Wittaya Chaiwangyen, Udo R. Markert University Hospital Jena. Department of Obstetrics. Placenta-Lab, Jena, Germany Background: Human placenta tissue exhibits a specific miRNA expression pattern that dynamically changes with the gestational age. This profile includes expression of a larger miRNA cluster located on the chromosome 14 (C14MC). Among these miRNAs, miR-134 is high expressed in first trimester but low in third trimester trophoblast cells. Recent reports suggested a role of miR-134 in the control of cell proliferation and invasion, but its function in trophoblast cells remains poorly understood. In this work, we aimed to investigate the role of miR-134 in the proliferation and invasion of HTR-8 cells. Material andmethods: Total RNAwas isolated fromHTR-8svneo cells using miRVana isolation kit. Expression of 43 miRNAs belonging to C14MC was quantitatively analysed by TaqMan Human MicroRNA Arrays. Expression of miR-134, miR-411 and miR-539 was confirmed by individual qPCR and normalized to RNU48. Silencing and overexpression of miR-134 was carried out by transfection with miR-134 miRIDIAN hairpin inhibitor, miR-134 mimic, or negative controls. Changes in cell viability, cell proliferation and invasion were assessed by MTS, BrdU and Matrigel assays, respectively. Results: C14MCmiRNAs are highly expressed in first trimester trophoblast cells and HTR-8 cells. Among them, 40miRNAs were down, and 6 were upregulated in third trimester trophoblast compared to first trimester. MiR134 was among the highest expressed miRNAs in HTR-8 cells. Silencing of

Expression of the presumptive chemokine Stromal Cell Derived Factor-2 (SDF-2) by different cell types in human placenta: function insights

Expression of the presumptive chemokine Stromal Cell Derived Factor-2 (SDF-2) by different cell types in human placenta: function insights

Arabidopsis Stromal-derived Factor2 (SDF2) Is a Crucial Target of the Unfolded Protein Response in the Endoplasmic Reticulum

Stresses increasing the load of unfolded proteins that enter the endoplasmic reticulum (ER) trigger a protective response termed the unfolded protein response (UPR). Stromal cell-derived factor2 (SDF2)-type proteins are highly conserved throughout the plant and animal kingdoms. In this study we have characterized AtSDF2 as crucial component of the UPR in Arabidopsis thaliana. Using a combination of biochemical and cell biological methods, we demonstrate that SDF2 is induced in response to ER stress conditions causing the accumulation of unfolded proteins. Transgenic reporter plants confirmed induction of SDF2 during ER stress. Under normal growth conditions SDF2 is highly expressed in fast growing, differentiating cells and meristematic tissues. The increased production of SDF2 due to ER stress and in tissues that require enhanced protein biosynthesis and secretion, and its association with the ER membrane qualifies SDF2 as a downstream target of the UPR. Determination of the SDF2 three-dimensional crystal structure at 1.95 A resolution revealed the typical beta-trefoil fold with potential carbohydrate binding sites. Hence, SDF2 might be involved in the quality control of glycoproteins. Arabidopsis sdf2 mutants display strong defects and morphological phenotypes during seedling development specifically under ER stress conditions, thus establishing that SDF2-type proteins play a key role in the UPR.

Isolation and characterization of a novel secretory protein, stromal cell-derived factor-2 (SDF-2) using the signal sequence trap method

With use of the signal sequence trap method, we isolated a cDNA encoding a novel secretory protein, SDF-2, from the mouse stromal cell line, ST2. The human homologue of SDF-2 was also isolated. The amino acid (aa) sequences deduced from both the clones were conserved more than 92%. The chromosomal localization of the human SDF-2 gene was mapped to 17q11.2. The aa sequence of SDF-2 shows similarity to those of yeast dolichyl phosphate- d-mannose:protein mannosyltransferases, Pmtlp [Strahl-Bolsinger et al. (1993) Proc. Natl. Acad. Sci. USA 90, 8164-8168] and Pmt2p [Lussier et al. (1995) J. Biol. Chem. 270, 2770-2775], whose activities have not been detected in higher eukaryotes.