851
|
Hirabayashi J, Ubukata T, Kasai K. Purification and molecular characterization of a novel 16-kDa galectin from the nematode Caenorhabditis elegans. J Biol Chem 1996; 271:2497-505. [PMID: 8576213 DOI: 10.1074/jbc.271.5.2497] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In our previous study (Hirabayashi, J., Satoh, M., Ohyama, Y., and Kasai, K. (1992) J. Biochem. (Tokyo) 111, 553-555), two beta-galactoside-binding lectins (apparent subunit molecular masses, 16 and 32 kDa, respectively) were identified in the nematode Caenorhabditis elegans. The subsequent study revealed that the 32-kDa lectin is a member of the galectin family. Since the 32-kDa galectin was found to consist of two homologous domains (approximately 16 kDa), 16-kDa lectin was thought to be a degradation product of the 32-kDa galectin. To clarify this, the 16-kDa lectin was purified by an improved procedure employing extraction with a calcium-supplemented buffer. The purified 16-kDa lectin was found to exist as a dimer (approximately 30 kDa) and showed hemagglutinating activity toward trypsinized rabbit erythrocytes, which was inhibited by lactose. Almost the whole sequence of the 16-kDa polypeptide (approximately 95%, 135 amino acids) was determined after digestion with various proteases. Based on the obtained information, a full-length cDNA was cloned with the aid of RNA-polymerase chain reaction. The clone encoded 146 amino acids including initiator methionine (calculated molecular mass, 15,928 Da). Based on these results, it was concluded that the 16-kDa lectin is a novel member of the galectin family, but not a degradation product of the 32-kDa galectin as had previously thought. However, the 16-kDa galectin showed relatively low sequence similarities to both the N-terminal and the C-terminal domains of the 32-kDa galectin (28% and 27% identities, respectively) and to various vertebrate galectins (14-27%). Nonetheless, all of the critical amino acids involved in carbohydrate binding were conserved. These observations suggest that, in spite of phylogenic distance between nematodes and vertebrates, both the 16-kDa and 32-kDa nematode isolectins have conserved essentially the same function(s) as those of vertebrate galectins, probably through recognition of a key disaccharide moiety, "N-acetyllactosamine."
Collapse
Affiliation(s)
- J Hirabayashi
- Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Kanagawa, Japan
| | | | | |
Collapse
|
852
|
Walzel H, Hirabayashi J, Kasai K, Brock J, Neels P. Cell calcium signalling induced by endogenous lectin carbohydrate interaction in the Jurkat T cell line. Glycoconj J 1996; 13:99-105. [PMID: 8785494 DOI: 10.1007/bf01049685] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effects of the beta-galactoside-binding lectin from human placenta (HPL14) on intracellular calcium concentration ([Ca2+]i) were examined in the human Jurkat T cell line. The lectin induces a concentration dependent increase in [Ca2+]i. This calcium signalling effect is clearly mediated through complementary cell surface galactoglycoconjugates because it can be blocked by beta-galactosides. The observed Ca2+ - response involves both the release of calcium from intracellular stores and a calcium influx from the extracellular space. It is sustained in the presence of 1 mM extracellular calcium whereas it becomes transient when the influx of extracellular calcium was blocked by calcium chelation to EGTA. Voltage-sensitive calcium channel blockers like verapamil and prenylamine were without effect on the action of HPL14. Protection of the sugar binding activity of HPL14 in the absence of a thiol-reducing reagent by carboxamidomethylation (CM-HPL14) or by substitution Cys2 with serine (C2S) results in lectin proteins with considerably decreased calcium signalling efficiency. The recombinant lectin (Rec H) and the mutant protein obtained by substitution of highly conservative Trp68 with tyrosine (W68Y) induce lower levels of [Ca2+]i compared to wild type lectin.
Collapse
Affiliation(s)
- H Walzel
- Institute of Medical Biochemistry, University of Rostock, Germany
| | | | | | | | | |
Collapse
|
853
|
Vasta GR, Ahmed H. Animal lectins as cell surface receptors: current status for invertebrate species. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 1996; 17:158-82. [PMID: 8822804 DOI: 10.1007/978-3-642-80106-8_8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- G R Vasta
- Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore 21202, USA
| | | |
Collapse
|
854
|
Leonidas DD, Elbert BL, Zhou Z, Leffler H, Ackerman SJ, Acharya KR. Crystal structure of human Charcot-Leyden crystal protein, an eosinophil lysophospholipase, identifies it as a new member of the carbohydrate-binding family of galectins. Structure 1995; 3:1379-93. [PMID: 8747464 DOI: 10.1016/s0969-2126(01)00275-1] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND The Charcot-Leyden crystal (CLC) protein is a major autocrystallizing constituent of human eosinophils and basophils, comprising approximately 10% of the total cellular protein in these granulocytes. Identification of the distinctive hexagonal bipyramidal crystals of CLC protein in body fluids and secretions has long been considered a hallmark of eosinophil-associated allergic inflammation. Although CLC protein possesses lysophospholipase activity, its role(s) in eosinophil or basophil function or associated inflammatory responses has remained speculative. RESULTS The crystal structure of the CLC protein has been determined at 1.8 A resolution using X-ray crystallography. The overall structural fold of CLC protein is highly similar to that of galectins -1 and -2, members of an animal lectin family formerly classified as S-type or S-Lac (soluble lactose-binding) lectins. This is the first structure of an eosinophil protein to be determined and the highest resolution structure so far determined for any member of the galectin family. CONCLUSIONS The CLC protein structure possesses a carbohydrate-recognition domain comprising most, but not all, of the carbohydrate-binding residues that are conserved among the galectins. The protein exhibits specific (albeit weak) carbohydrate-binding activity for simple saccharides including N-acetyl-D-glucosamine and lactose. Despite CLC protein having no significant sequence or structural similarities to other lysophospholipase catalytic triad has also been identified within the CLC structure, making it a unique dual-function polypeptide. These structural findings suggest a potential intracellular and/or extracellular role(s) for the galectin-associated activities of CLC protein in eosinophil and basophil function in allergic diseases and inflammation.
Collapse
Affiliation(s)
- D D Leonidas
- School of Biology and Biochemistry, University of Bath, Claverton Down, UK
| | | | | | | | | | | |
Collapse
|
855
|
Abstract
Galectin-1, a member of the family of beta-galactoside binding proteins, has growth regulatory and immunomodulatory activities. We report here that galectin-1, expressed by stromal cells in human thymus and lymph nodes, is present at sites of cell death by apoptosis during normal T-cell development and maturation. Galectin-1 induced apoptosis of activated human T cells and human T leukaemia cell lines. Resting T cells also bound galectin-1, but did not undergo apoptosis. Human endothelial cells that expressed galectin-1 induced apoptosis of bound T cells. Galectin-1-induced apoptosis required expression of CD45, and was decreased when N-glycan elongation was blocked by treatment of the cells by swainsonine, whereas inhibition of O-glycan elongation potentiated the apoptotic effect of galectin-1. Induction of apoptosis by an endogenous mammalian lectin represents a new mechanism for regulating the immune response.
Collapse
Affiliation(s)
- N L Perillo
- UCLA Department of Pathology and Laboratory Medicine, Los Angeles, California 90095-1732, USA
| | | | | | | |
Collapse
|
856
|
Mathews KP, Konstantinov KN, Kuwabara I, Hill PN, Hsu DK, Zuraw BL, Liu FT. Evidence for IgG autoantibodies to galectin-3, a beta-galactoside-binding lectin (Mac-2, epsilon binding protein, or carbohydrate binding protein 35) in human serum. J Clin Immunol 1995; 15:329-37. [PMID: 8576319 DOI: 10.1007/bf01541323] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Galectin-3 is a beta-galactoside-binding animal lectin formerly called epsilon protein, Mac-2, carbohydrate binding protein 35, CBH 30, L-29, or L34. The possible occurrence of autoantibodies to galectin-3 was investigated because crosslinking of galectins bound to IgE or Fc epsilon RI might produce mediator release from mast cells or basophils. Unexpectedly, a control serum from an individual free of current allergic symptoms was found to have a significantly elevated level of IgG anti-galectin-3 by ELISA employing galectin-3-coated wells incubated with test serum followed by HRPO-conjugated goat anti-human IgG. The reaction was not inhibitable by lactose, suggesting that it is not a result of binding of IgG by galectin-3 through lectin-carbohydrate interactions. The antibody activity was specifically adsorbed by galectin-3 and protein A-conjugated Sepharose and was associated primarily with subclass IgG1. The presence of the antibodies was confirmed by immunoblotting showing binding of IgG to the 30-kD galectin-3 band. The relevant epitopes were in the galectin-3 N-terminal domain. The propositus was subsequently found to have adenocarcinoma of the colon, and titers of IgG anti-galectin-3 were found to be sharply elevated after hemicolectomy. Similar antibody titers have not been found in family members, but small numbers of normal persons and patients with malignant neoplasms have been found to have evidence of IgG anti-galectin-3 antibodies at lower titers than the propositus. The pathogenesis of this autoimmune reaction is unclear, though there is a trend for it to occur in older persons.
Collapse
Affiliation(s)
- K P Mathews
- Department of Molecular & Experimental Medicine, Scripps Research Institute, La Jolla, California 92037, USA
| | | | | | | | | | | | | |
Collapse
|
857
|
Salvatore P, Contursi C, Benvenuto G, Bruni CB, Chiariotti L. Characterization and functional dissection of the galectin-1 gene promoter. FEBS Lett 1995; 373:159-63. [PMID: 7589457 DOI: 10.1016/0014-5793(95)01032-a] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The galectin-1 gene encodes a beta-galactoside-binding protein whose overexpression is associated with neoplastic transformation and loss of differentiation. Transient transfection assays of a series of deletions constructs (pGAT) showed that the galectin-1 promoter is highly active in cells both expressing and non-expressing the endogenous gene, and that the basal activity is determined by sequences encompassing the transcription start site (-50/+50). Both an upstream (-50/-26) and a downstream position-dependent (+10/+50) cis-elements are necessary for efficient transcriptional activity and are able to bind nuclear proteins.
Collapse
Affiliation(s)
- P Salvatore
- Dipartimento di Biologia e Patologia Cellulare e Molecolare L. Califano, Università degli Studi di Napoli Federico II, Italy
| | | | | | | | | |
Collapse
|
858
|
Abstract
The number of animal proteins known to recognize carbohydrates and the number of their biological roles continue to increase. Comparisons of primary structures show that some of the newly described lectins are akin to previously investigated lectins, whereas others represent new structural groups. Progress has been made in understanding structure-function relationships for several lectins in both the old and the new categories.
Collapse
Affiliation(s)
- K Drickamer
- Department of Biochemistry, University of Oxford, UK
| |
Collapse
|
859
|
Abstract
Several important advances in the structure determination of animal lectins were made in the past year. The X-ray crystal structures of trimeric fragments of the human and rat mannose-binding proteins have defined for the first time the three-dimensional subunit organization of a multimeric C-type lectin. In addition, the structure of a galectin-biantennary oligosaccharide complex has provided a model for what might be biochemically relevant cross-linking interactions. Finally, in a novel variation on lectin cross-linking, independent carbohydrate-binding sites on basic fibroblast growth factor have been found to recognize opposing faces of a synthetic heparin/heparan sulphate fragment, leading to growth-factor polymerization.
Collapse
Affiliation(s)
- J M Rini
- Department of Molecular and Medical Genetics, University of Toronto, Ontario, Canada
| |
Collapse
|
860
|
Vlassara H, Li YM, Imani F, Wojciechowicz D, Yang Z, Liu FT, Cerami A. Identification of Galectin-3 As a High-Affinity Binding Protein for Advanced Glycation End Products (AGE): A New Member of the AGE-Receptor Complex. Mol Med 1995. [DOI: 10.1007/bf03401604] [Citation(s) in RCA: 279] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
861
|
Bao Q, Hughes RC. Galectin-3 expression and effects on cyst enlargement and tubulogenesis in kidney epithelial MDCK cells cultured in three-dimensional matrices in vitro. J Cell Sci 1995; 108 ( Pt 8):2791-800. [PMID: 7593320 DOI: 10.1242/jcs.108.8.2791] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Galectin-3 is a member of a closely related family of beta-galactoside-binding soluble proteins found in many vertebrate epithelial and myeloid cell types. The developmentally regulated presence of galectin-3 in tissues, for example kidney, and an affinity for many cell-surface and matrix glycoproteins indicate its importance in extracellular biological processes. Since a polarised expression and secretion of galectin-3 was observed in monolayer-cultured MDCK cells, an understanding of the secretion and distribution of this lectin in a three-dimensional in vitro model would help to uncover its role(s) in the interplay between cell-surface adhesion molecules and extracellular matrix components occurring during cell aggregation and polarisation in tissue formation. In this study, the cellular distribution and secretion of galectin-3 were examined in MDCK cells cultured within a gel matrix. MDCK cells were cultured within type I collagen or Matrigel to obtain multicellular cysts, and tubule formation was induced in collagen gels with hepatocyte growth factor. Immunofluorescent staining of these structures using antibodies against galectin-3 and other cell-surface domain markers was carried out either in situ or on cryosections and was visualised by confocal and conventional epifluorescence microscopy. Our results show that MDCK cells suspended in hydrated collagen gels or Matrigel exhibit differential and polarised galectin-3 expression on the baso-lateral surface domains of cells lining the cysts. The lectin is colocalised with laminin on the basal surface. In tubule-forming cysts, galectin-3 is excluded from the initial spikes and the progressing tips of the tubules although its basolateral expression on the cyst body remains. Galectin-3 added exogenously to cultures, as well as antibodies against laminin subunits and integrin beta 1 subunit, exerted an inhibitory effect on cyst enlargement of MDCK cells in 3-D Matrigel while galectin-3-specific antibodies could promote this process. The results suggest that galectin-3 exerts its effect on MDCK cells in a three-dimensional environment through modulation of both cell-cell and cell-substratum adhesions, and the interplay between these adhesions is important in the growth of multicellular aggregates and extensions occurring during normal kidney tubulogenesis.
Collapse
Affiliation(s)
- Q Bao
- National Institute for Medical Research, Mill Hill, London, UK
| | | |
Collapse
|
862
|
Puche AC, Key B. Identification of cells expressing galectin-1, a galactose-binding receptor, in the rat olfactory system. J Comp Neurol 1995; 357:513-23. [PMID: 7673482 DOI: 10.1002/cne.903570403] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Interactions between carbohydrate ligands and their receptors play an important role in cell adhesion and migration in many tissues. Cell-surface carbohydrates that contain terminal galactose have previously been implicated in primary sensory axon growth in the rodent olfactory system. The aim of the present study was to determine whether galectin-1, a galactose-binding receptor, was expressed within the rat primary olfactory pathway. Immunohistochemical and in situ hybridisation analyses revealed expression of galectin-1 by primary sensory olfactory neurons during the major embryonic period of axonogenesis as well as in maturity. In the adult olfactory bulb, galectin-1 was expressed by both second-order projection neurons and interneurons and was selectively localised to the synaptic neuropil layers. Mitral cells, the principal postsynaptic target of primary olfactory axons, began expressing this lectin soon after genesis and maintained high levels into adulthood. The expression of galectin-1 in the primary olfactory pathway and olfactory bulb neuropil suggests a role for this lectin both in the initial formation and in the subsequent maintenance of neuronal connections between the peripheral and the central olfactory neurons as well as between neurons within the bulb.
Collapse
Affiliation(s)
- A C Puche
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Victoria, Australia
| | | |
Collapse
|
863
|
Chiariotti L, Berlingieri MT, Battaglia C, Benvenuto G, Martelli ML, Salvatore P, Chiappetta G, Bruni CB, Fusco A. Expression of galectin-1 in normal human thyroid gland and in differentiated and poorly differentiated thyroid tumors. Int J Cancer 1995; 64:171-5. [PMID: 7622305 DOI: 10.1002/ijc.2910640305] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We previously reported that galectin-1 gene expression increases up to 100-fold in oncogene-transformed rat thyroid cells compared with their normal counterparts and that the relative mRNA levels correlate with the degree of malignancy. In the present study we investigated whether galectin-1 is differentially expressed in human thyroid neoplasms, which range from well-differentiated tumors to undifferentiated anaplastic carcinomas. We analyzed 74 human thyroid specimens of neoplastic, hyperproliferative and normal tissues and several tumor cell lines. Galectin-1 mRNA and protein levels were higher in 6 thyroid carcinoma-derived cell lines than in normal thyroid primary cultures and adenoma cells. Galectin-1 mRNA levels increased in 28/40 papillary carcinomas and in 6/7 anaplastic carcinomas compared with normal or hyperplastic thyroid. Conversely, galectin-1 expression was unaffected in follicular carcinomas and benign adenomas. Immunohistochemical analysis of normal thyroid and papillary carcinoma sections revealed a higher content of galectin-1 protein in neoplastic follicular cells than in normal cells.
Collapse
Affiliation(s)
- L Chiariotti
- Centro di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Richerche, Dipartimento di Biologia e Patologia Cellulare e Molecolare L. Califano, Università degli Studi di Napoli, Federico II, Naples, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
864
|
Schoeppner HL, Raz A, Ho SB, Bresalier RS. Expression of an endogenous galactose-binding lectin correlates with neoplastic progression in the colon. Cancer 1995; 75:2818-26. [PMID: 7773932 DOI: 10.1002/1097-0142(19950615)75:12<2818::aid-cncr2820751206>3.0.co;2-#] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Galectin-3 is an endogenous galactose-binding protein that is expressed in a wide range of normal and neoplastic tissues and is thought to be involved in cellular adhesion and growth regulation. Conflicting data have been reported regarding the expression of galectin-3 during carcinogenesis in the colon. METHODS The authors studied the expression of galectin-3 in 153 tissue specimens, including 29 adenomas containing early cancer, 66 colon carcinomas of known Dukes' stage with available long term patient survival data, and 23 additional primary carcinomas with 35 associated metastases. An immunohistochemical scoring system was used that considers tumor heterogeneity and yields an integrated numeric score subject to statistical analysis. Genetically related colon cancer cells with different metastatic capabilities also were compared by Western blot analysis. RESULTS Galectin-3 expression was significantly higher in high grade dysplasia and early invasive cancers compared with the adenomatous tissue from which they evolved (mean staining score, 2.33 vs. 1.15; P = 0.001). Galectin-3 expression in invasive cancers varied according to Dukes' stage, indicating a linear relationship with advancing stage (P = 0.008). Enhanced expression correlated with decreased long term patient survival (P = 0.021). Metastases expressed a higher level of galectin-3 compared with the primary cancers from which they evolved (P < 0.005) as did cultured cells of high metastatic capability compared with their counterparts with low metastatic potential. CONCLUSION Galectin-3 expression in colonic mucosa is related to neoplastic transformation and metastatic progression.
Collapse
Affiliation(s)
- H L Schoeppner
- Gastrointestinal Cancer Research Laboratory, Henry Ford Health Sciences Center, Detroit, Michigan 48202, USA
| | | | | | | |
Collapse
|
865
|
Craig SS, Krishnaswamy P, Irani AM, Kepley CL, Liu FT, Schwartz LB. Immunoelectron microscopic localization of galectin-3, an IgE binding protein, in human mast cells and basophils. Anat Rec (Hoboken) 1995; 242:211-9. [PMID: 7668406 DOI: 10.1002/ar.1092420210] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Galectin-3 is an endogenous soluble lectin within the family called galectins that bind beta-galactosides. Homologs of the protein isolated from different sources were previously designated as IgE-binding protein (epsilon BP), CBP35, CPB30, Mac-2, RL-29, RLL, L-29, and HL-29. All are now renamed galectin-3. This lectin is widely distributed in cells and tissues of mice, rats, dogs, hamsters, and humans. Light microscopic immunohistochemistry and ultrastructural immunogold labeling methods were used to determine the distribution of galectin-3 in human mast cells of several organs, in mast cells developed in vitro from human fetal liver cells, and in human peripheral blood basophils. Immunolabeling for the protein was observed in mast cells from all sources and in basophils. The lectin was detected in the nucleus and/or the cytoplasm. The nuclear labeling was over heterochromatin whereas euchromatin was unlabeled. Cytoplasmic labeling was concentrated over secretory granules. The intensity of staining generally was greater in mast cells of skin when compared with that of mast cells in other locations and with that of basophils. Studies have indicated that in mast cells galectin-3 may be involved in promoting their adhesion to basal laminae. In this study the localization of galectin-3 in the secretory granules of human mast cells and basophils suggests that these cells may release this lectin when activated to degranulate.
Collapse
Affiliation(s)
- S S Craig
- Department of Anatomy, Virginia Commonwealth University, Richmond 23298, USA
| | | | | | | | | | | |
Collapse
|
866
|
Fowlis D, Colnot C, Ripoche MA, Poirier F. Galectin-3 is expressed in the notochord, developing bones, and skin of the postimplantation mouse embryo. Dev Dyn 1995; 203:241-51. [PMID: 7655085 DOI: 10.1002/aja.1002030211] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The galectins are a family of low molecular weight, calcium-independent mammalian carbohydrate binding proteins that exhibit specificity for beta-galactoside derivatives. We have examined the expression pattern of galectin-3 in the developing mouse embryo by in situ hybridisation and immunohistochemistry. In the embryo proper, galectin-3 message and protein are first detected in notochord, starting from 8.5 days post coitum (dpc), and persist until this structure disappears. Galectin-3 is later found in cartilage primordia and in developing skin from 13.5 dpc. This very restricted and dynamic pattern suggests that galectin-3 may participate in the establishment and/or maintenance of notochord as well as the formation of cartilage and differentiation of skin. Finally, we find that galectin-3, which is identical to the macrophage marker Mac-2, is also expressed in embryonic macrophages.
Collapse
Affiliation(s)
- D Fowlis
- Unité INSERM 257, ICGM, Paris, France
| | | | | | | |
Collapse
|
867
|
Ramkumar R, Surolia A, Podder SK. Energetics of carbohydrate binding by a 14 kDa S-type mammalian lectin. Biochem J 1995; 308 ( Pt 1):237-41. [PMID: 7755570 PMCID: PMC1136868 DOI: 10.1042/bj3080237] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The thermodynamics of the binding of derivatives of galactose and lactose to a 14 kDa beta-galactoside-binding lectin (L-14) from sheep spleen has been studied in 10 nM phosphate/150 mM NaCl/10 mM beta-mercaptoethanol buffer, pH 7.4, and in the temperature range 285-300 K using titration calorimetry. The single-site binding constants of various sugars for the lectin were in the following order: N-acetyl-lactosamine thiodigalactoside > 4-methylumbelliferyl lactoside > lactose > 4-methylumbelliferyl alpha-D-galactoside > methyl-alpha-galactose > methyl-beta-galactose. Reactions were essentially enthalpically driven with the binding enthalpies ranging from -53.8 kJ/mol for thiodigalactoside at 301 K to -2.2 kJ/mol for galactose at 300 K, indicating that hydrogen-bonding and van der Waals interactions provide the major stabilization for these reactions. However, the binding of 4-methylumbelliferyl-alpha-D-galactose displays relatively favourable entropic contributions, indicating the existence of a non-polar site adjacent to the galactose-binding subsite. From the increments in the enthalpies for the binding of lactose, N-acetyl-lactosamine and thiodigalactoside relative to methyl-beta-galactose, the contribution of glucose binding in the subsite adjacent to that for galactose shows that glucose makes a major contribution to the stability of L-14 disaccharide complexes. Observation of enthalpy-entropy compensation for the recognition of saccharides such as lactose by L-14 and the absence of it for monosaccharides such as galactose, together with the lack of appreciable changes in the heat capacity (delta Cp), indicate that reorganization of water plays an important role in these reactions.
Collapse
Affiliation(s)
- R Ramkumar
- Department of Biochemistry, Indian Institute of Science, Bangalore
| | | | | |
Collapse
|
868
|
Raimond J, Rouleux F, Monsigny M, Legrand A. The second intron of the human galectin-3 gene has a strong promoter activity down-regulated by p53. FEBS Lett 1995; 363:165-9. [PMID: 7729540 DOI: 10.1016/0014-5793(95)00310-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Galectin-3 is a galactose-specific lectin which has been shown to be involved in several biological functions such as cell growth regulation, cell aggregation and cell differentiation. The partial cloning of the human genomic sequences reveals the presence of a 651 bp intron, 18 bp downstream of the translation initiation site. This intron contains several regulatory elements found in many eukaryotic genes. This sequence, when inserted upstream of a promoter-free luciferase gene, induces the expression of luciferase, demonstrating the promoter activity of the intron upon transfection in human or murine cells. This promoter activity is down-modulated by wild-type p53 but not by a mutated form of p53.
Collapse
Affiliation(s)
- J Raimond
- Laboratoire de Biochimie des Glycoconjugués et Lectines Endogènes, Centre de Biophysique Moléculaire du CNRS, Orléans, France
| | | | | | | |
Collapse
|
869
|
Abstract
Neural-recognition molecules are carbohydrate-bearing glycoproteins, glycolipids or proteoglycans that are found at the cell surface or in the extracellular matrix that regulate cell interactions during development, modification of synaptic activity and regeneration of nerve connections after damage in the adult. The expression of the carbohydrates appears to be fine tuned to these functions. Among the identified carbohydrates are polysialic acid, a 3'-sulfated glucuronic acid, and oligomannosidic residues. They act not only between apposing partner cell surfaces (trans-interaction) but also between recognition molecules within the surface membrane of one cell (cis-interaction), thereby forming complexes that influence transduction of signals to the cell interior.
Collapse
Affiliation(s)
- M Schachner
- Dept of Neurobiology, Swiss Federal Institute of Technology, Hönggerberg, Zürich
| | | |
Collapse
|
870
|
Akimoto Y, Hirabayashi J, Kasai K, Hirano H. Expression of the endogenous 14-kDa beta-galactoside-binding lectin galectin in normal human skin. Cell Tissue Res 1995; 280:1-10. [PMID: 7750127 DOI: 10.1007/bf00304505] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The localization of an endogenous 14-kDa beta-galactoside-binding lectin (galectin) and its pattern of gene expression were examined in normal human skin by light- and electron microscopy. Under the light microscope, immunostaining of 14-kDa galectin was observed in the cell membrane of cells in the basal and spinous layers of the epidermis. Galectin was also found in the Langerhans cells, as shown by double labeling using anti-14-kDa galectin and anti-CD1a antibodies. In the dermis, immunostaining for the 14-kDa galectin was positive in the extracellular matrix and fibroblasts. At the electron-microscopic level of resolution, galectin was located primarily along the plasma membrane of keratinocytes, and in both the cytoplasm and nucleus of Langerhans cells in the epidermis, whereas in the dermis it was detected in the extracellular matrix and in both the nucleus and cytoplasm of fibroblasts. The gene expression of 14-kDa galectin was visualized by the HRP-staining method following in situ hybridization techniques. The expression was detected in the cytoplasm of cells in the basal and spinous layers of the epidermis; whereas, in the dermis, it was detected in the cytoplasm of fibroblasts. Moreover, SDS-polyacrylamide gel electrophoresis and lectin-blot analysis revealed that this galectin bound to glycoproteins of approximately 17, 62, and 72 kDa in the epidermis and to those of 29, 54, and 220 kDa in the dermis. The present study indicates that 1) normal human skin produces the beta-galactoside-binding 14-kDa galectin, and 2) this galectin is located in both the epidermis, particularly in the keratinocytes and Langerhans cells, and in the dermis. These results suggest that galectin is important for cell-cell contact and/or adhesion in the epidermis and for cell-extracellular matrix interaction in the dermis.
Collapse
Affiliation(s)
- Y Akimoto
- Department of Anatomy, Kyorin University School of Medicine, Tokyo, Japan
| | | | | | | |
Collapse
|
871
|
Madsen P, Rasmussen HH, Flint T, Gromov P, Kruse TA, Honoré B, Vorum H, Celis JE. Cloning, expression, and chromosome mapping of human galectin-7. J Biol Chem 1995; 270:5823-9. [PMID: 7534301 DOI: 10.1074/jbc.270.11.5823] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The galectins are a family of beta-galactoside-binding proteins implicated in modulating cell-cell and cell-matrix interactions. Here we report the cloning and expression of a novel member of this family (galectin-7) that correspond to IEF (isoelectric focusing) 17 (12,700 Da; pI, 7.6) in the human keratinocyte protein data base, and that is strikingly down-regulated in SV40 transformed keratinocytes (K14). The cDNA was cloned from a lambda gt11 cDNA expression library using degenerated oligodeoxyribonucleotides back-translated from an IEF 17 peptide sequence. The protein encoded by the galectin-7 clone comigrated with IEF 17 as determined by two-dimensional (two-dimensional gel electrophoresis) analysis of proteins expressed by transiently transfected COS-1 cells, and bound lactose. Alignment of the amino acid sequences with other members of the family showed that the amino acids central to the beta-galactoside interaction are conserved. Galectin-7 was partially externalized to the medium by keratinocytes although it has no typical secretion signal peptide. Immunoblotting as well as immunofluorescence analysis of human tissues with a specific galectin-7 antibody revealed a narrow distribution of the protein which was found mainly in stratified squamous epithelium. The antigen localized to basal keratinocytes, although it was also found, albeit at lower levels, in the suprabasal layers where it concentrated to areas of cell to cell contact. Both, its cellular localization as well as its striking down-regulation in K14 keratinocytes imply a role in cell-cell and/or cell-matrix interactions necessary for normal growth control. The galectin-7 gene was mapped to chromosome 19.
Collapse
Affiliation(s)
- P Madsen
- Department of Medical Biochemistry, University of Aarhus, Denmark
| | | | | | | | | | | | | | | |
Collapse
|
872
|
Gitt MA, Wiser MF, Leffler H, Herrmann J, Xia YR, Massa SM, Cooper DN, Lusis AJ, Barondes SH. Sequence and mapping of galectin-5, a beta-galactoside-binding lectin, found in rat erythrocytes. J Biol Chem 1995; 270:5032-8. [PMID: 7890611 DOI: 10.1074/jbc.270.10.5032] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A monomeric rat beta-galactoside-binding lectin previously purified from extracts of rat lung has been localized to erythrocytes, and the cDNA encoding it has been isolated from a rat reticulocyte cDNA library. The deduced amino acid sequence of the cDNA predicts a protein with a M(r) of 16,199, with no evidence of a signal peptide. The deduced sequence is identical to the sequences of seven proteolytic peptides derived from the purified lectin. Peptide analysis by mass spectrometry indicates that the N-terminal methionine is cleaved and that serine 2 is acetylated. The lectin shares all the strictly conserved amino acid residues of other members of the mammalian galectin family and is designated galectin-5 (GenBank accession number L36862). Galectin-5 is a weak agglutinin of rat erythrocytes, despite its monomeric structure. The gene encoding galectin-5 (LGALS5) has been mapped in mouse to chromosome 11, approximately 50 centimorgans from the centromere and 1.8 +/- 1.8 centimorgans from the polymorphic marker D11Mit34n, a region syntenic with human chromosome 17q11.
Collapse
Affiliation(s)
- M A Gitt
- Department of Psychiatry, University of California, San Francisco 94143-0984
| | | | | | | | | | | | | | | | | |
Collapse
|
873
|
Cho M, Cummings RD. Galectin-1, a beta-galactoside-binding lectin in Chinese hamster ovary cells. I. Physical and chemical characterization. J Biol Chem 1995; 270:5198-206. [PMID: 7890630 DOI: 10.1074/jbc.270.10.5198] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We report our studies on the characterization of an approximately 14-kDa lectin, termed galectin-1 that we have found to be expressed by Chinese hamster ovary (CHO) cells. cDNA for galectin-1 from CHO cells was prepared and sequenced, and a recombinant form (rGal-1) was expressed in Escherichia coli. A mutated form of the protein that fully retained activity was also constructed (termed C2SrGal-1) in which Cys-2 was changed to Ser-2. rGal-1 was stable in the presence of reducing agent, but it quickly lost all activity in the absence of reducing agent. In contrast, glycoprotein ligands, such as basement membrane laminin, stabilized the activity of rGal-1 in the absence of reducing agent (t1/2 = 2 weeks). C2SrGal-1 was stable in the presence or absence of either ligand or reducing agent. Unexpectedly, galectin-1 was found to exist in a reversible and active monomer-dimer equilibrium with a Kd approximately 7 microM and an equilibration time of t1/2 approximately 10 h. Addition of haptenic sugars did not affect this equilibrium. Galectin-1 isolated from the cytosol of CHO cells was found to exist as monomers and dimers. These studies demonstrate that galectin-1 binding to a biological ligand stabilizes its activity and that the monomer/dimer state of the protein is regulated by lectin concentration.
Collapse
Affiliation(s)
- M Cho
- University of Oklahoma Health Sciences Center, Department of Biochemistry and Molecular Biology, Oklahoma City 73190
| | | |
Collapse
|
874
|
Cho M, Cummings RD. Galectin-1, a beta-galactoside-binding lectin in Chinese hamster ovary cells. II. Localization and biosynthesis. J Biol Chem 1995; 270:5207-12. [PMID: 7890631 DOI: 10.1074/jbc.270.10.5207] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In the accompanying study (Cho, M., and Cummings, R. D. (1995) J. Biol. Chem. 270, 5198-5206), we reported that Chinese hamster ovary (CHO) cells synthesize galectin-1. We have now used several approaches to define the subcellular location and biosynthesis of galectin-1 in these cells. Galectin-1 was present on the cell surface, as assessed by immunofluorescent staining with monospecific antibody to the protein. Quantitation of the surface-localized galectin-1 was achieved by metabolically radiolabeling cells with [35S]Met/Cys and measuring the amount of lectin (i) sensitive to trypsin, (ii) accessible to biotinylating reagents, and (iii) accessible to the haptenic disaccharide lactose. By all three procedures, approximately 1/2 of the radiolabeled galectin-1 associated with cells was shown to be on the cell surface with the remainder intracellular. The kinetics of externalization of galectin-1 was monitored by pulse-chase radiolabeling, and it was shown that cells secrete the protein with a t1/2 approximately 20 h. The cell surface form of galectin-1 in CHO cells was active and bound to surface glycoconjugates, but lectin accumulating in the culture media was inactive. Lectin synthesized by mutant Lec8 CHO cells, which are unable to galactosylate glycoproteins was not found on the surface and quantitatively accumulated in the media in an inactive form. Taken together, our results demonstrate that galectin-1 is quantitatively externalized by CHO cells and can associate with surface glycoconjugates where the lectin activity is stabilized.
Collapse
Affiliation(s)
- M Cho
- University of Oklahoma Health Sciences Center, Department of Biochemistry and Molecular Biology, Oklahoma City 73190
| | | |
Collapse
|
875
|
Baum LG, Pang M, Perillo NL, Wu T, Delegeane A, Uittenbogaart CH, Fukuda M, Seilhamer JJ. Human thymic epithelial cells express an endogenous lectin, galectin-1, which binds to core 2 O-glycans on thymocytes and T lymphoblastoid cells. J Exp Med 1995; 181:877-87. [PMID: 7869048 PMCID: PMC2191916 DOI: 10.1084/jem.181.3.877] [Citation(s) in RCA: 197] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Thymic epithelial cells play a crucial role in the selection of developing thymocytes. Thymocyte-epithelial cell interactions involve a number of adhesion molecules, including members of the integrin and immunoglobulin superfamilies. We found that human thymic epithelial cells synthesize an endogenous lectin, galectin-1, which binds to oligosaccharide ligands on the surface of thymocytes and T lymphoblastoid cells. Binding of T lymphoblastoid cells to thymic epithelial cells was inhibited by antibody to galectin-1 on the epithelial cells, and by two antibodies, T305 and 2B11, that recognize carbohydrate epitopes on the T cell surface glycoproteins CD43 and CD45, respectively. T lymphoblastoid cells and thymocytes bound recombinant galectin-1, as demonstrated by flow cytometric analysis, and lectin binding was completely inhibited in the presence of lactose. The degree of galectin-1 binding to thymocytes correlated with the maturation stage of the cells, as immature thymocytes bound more galectin-1 than did mature thymocytes. Preferential binding of galectin-1 to immature thymocytes may result from regulated expression of preferred oligosaccharide ligands on those cells, since we found that the epitope recognized by the T305 antibody, the core 2 O-glycan structure on CD43, was expressed on cortical, but not medullary cells. The level of expression of the UDP-GlcNAc:Gal beta 1,3GalNAc-R beta 1, 6GlcNAc transferase (core 2 beta 1, 6 GlcNAc transferase, or C2GnT), which creates the core 2 O-glycan structure, correlated with the glycosylation change between cortical and medullary cells. Expression of mRNA encoding the C2GnT was high in subcapsular and cortical thymocytes and low in medullary thymocytes, as demonstrated by in situ hybridization. These results suggest that galectin-1 participates in thymocyte-thymic epithelial cell interactions, and that this interaction may be regulated by expression of relevant oligosaccharide ligands on the thymocyte cell surface.
Collapse
Affiliation(s)
- L G Baum
- Department of Pathology and Laboratory Medicine, UCLA School of Medicine 90024
| | | | | | | | | | | | | | | |
Collapse
|
876
|
Mehul B, Bawumia S, Hughes RC. Cross-linking of galectin 3, a galactose-binding protein of mammalian cells, by tissue-type transglutaminase. FEBS Lett 1995; 360:160-4. [PMID: 7875321 DOI: 10.1016/0014-5793(95)00100-n] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The 30 kDa beta-galactoside-binding protein of baby hamster kidney (BHK) cells [Mehul et al. (1994), J. Biol. Chem. 269, 18250-18258] homologous to galectin 3, a widely distributed mammalian lectin, has been found to be a substrate for tissue type transglutaminase, as shown by the incorporation in a calcium- and time-dependent manner of 5-(biotinamido) pentylamine in the presence of guinea pig liver transglutaminase. The amino-terminal domain of hamster galectin 3, which is a repetitive sequence rich in glutamine, tyrosine, glycine and proline, is also an excellent substrate. A single lysine residue in the N-terminal domain is an essential requirement for transglutaminase-mediated oligomerization, and two equivalent glutamine residues present in identical sequence repeats within this domain appear to be involved as amine acceptors in cross-linking reactions. Transglutaminase-mediated cross-linking of galectin 3 to itself or to matrix components may be one mechanism for stabilisation of a multivalent binding form of the lectin in cell secretions or in extracellular matrices.
Collapse
Affiliation(s)
- B Mehul
- National Institute for Medical Research, Ridgeway, London, UK
| | | | | |
Collapse
|
877
|
Hatakeyama T, Nagatomo H, Yamasaki N. Interaction of the hemolytic lectin CEL-III from the marine invertebrate Cucumaria echinata with the erythrocyte membrane. J Biol Chem 1995; 270:3560-4. [PMID: 7876091 DOI: 10.1074/jbc.270.8.3560] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
CEL-III is one of four Ca(2+)-dependent galactose/N-acetylgalactosamine (GalNAc)-binding lectins from the marine invertebrate Cucumaria echinata which exhibits hemolytic activity, especially toward rabbit and human erythrocytes. The hemolytic activity of CEL-III was also Ca(2+)-dependent and was found to be inhibited by galactose or GalNAc-containing carbohydrates, suggesting that the hemolysis was caused by CEL-III binding to specific carbohydrates on the erythrocyte membrane by Ca(2+)-dependent lectin activity, followed by partial destruction of the membrane. The activity of CEL-III was highest at 10 degrees C and decreased markedly with increasing temperature, unlike usual enzymatic reactions. The hemolytic activity of CEL-III increased with increasing pH from neutral to 10, but almost no hemolysis was observed below pH 6.5. Immunoblotting analysis of proteins from the erythrocyte membrane after treatment with CEL-III indicated that CEL-III aggregates were irreversibly bound to the membrane. When erythrocytes were incubated with CEL-III in the presence of dextran with molecular masses greater than 4 kDa, lysis was impeded considerably, while a concomitant release of ATP was detected from these osmotically protected cells. It was found that CEL-III released carboxyfluorescein from artificial globoside-containing lipid vesicles, and it is suggested that CEL-III is a novel pore-forming protein with the characteristics of a Ca(2+)-dependent lectin, which may act as a toxic protein to foreign microorganisms.
Collapse
Affiliation(s)
- T Hatakeyama
- Laboratory of Biochemistry, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | | | | |
Collapse
|
878
|
Arar C, Carpentier V, Le Caer JP, Monsigny M, Legrand A, Roche AC. ERGIC-53, a membrane protein of the endoplasmic reticulum-Golgi intermediate compartment, is identical to MR60, an intracellular mannose-specific lectin of myelomonocytic cells. J Biol Chem 1995; 270:3551-3. [PMID: 7876089 DOI: 10.1074/jbc.270.8.3551] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A mannose-specific membrane lectin (MR60) isolated from human myelomonocytic HL60 cells by affinity chromatography is expressed in intracellular organelles of immature monocytes (Pimpaneau, V., Midoux, P., Monsigny, M., and Roche, A. C. (1991) Carbohydr. Res. 213, 95-108). It is not present at the cell surface and is immunochemically and structurally distinct from the M(r) 175,000 mannose receptor of mature macrophages. MR60 cDNA was isolated and characterized; on the basis of its sequence, MR60 is not related to any known mammalian lectins. Surprisingly, MR60 was found to be identical to ERGIC-53 (Schindler, R., Itin, C., Zerial, M., Lottspeich, F., and Hauri, H.P. (1993) Eur. J. Cell Biol. 61, 1-9), a type I integral membrane protein, defined as a marker of the intermediate compartment that recycles between the Golgi apparatus and endoplasmic reticulum; MR60/ERGIC-53 shares with VIP-36 significant homologies with leguminous plant lectins (Fiedler, K., and Simmons, K. (1994) Cell 77, 625-626). We extend these findings in evidencing a structural homology between MR60/ERGIC-53 and mammalian galectins (soluble beta galactose binding proteins). MR60/ERGIC-53 is the first lectin characterized as an endoplasmic reticulum-Golgi protein. Accordingly, this intracellular mannose binding protein could be involved in the traffic of glycoproteins between endoplasmic reticulum and the Golgi apparatus.
Collapse
Affiliation(s)
- C Arar
- Laboratoire de Biochemie des Glycoconjugués et Lectines Endogènes, Université d'Orléans, France
| | | | | | | | | | | |
Collapse
|
879
|
Hadari YR, Paz K, Dekel R, Mestrovic T, Accili D, Zick Y. Galectin-8. A new rat lectin, related to galectin-4. J Biol Chem 1995; 270:3447-53. [PMID: 7852431 DOI: 10.1074/jbc.270.7.3447] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A protein of 35 kDa which has the characteristic properties of galectins (S-type lectins) was cloned from rat liver cDNA expression library. Since names for galectins 1-7 were already assigned, this new protein was named galectin-8. Three lines of evidence demonstrate that galectin-8 is indeed a novel galectin: (i) its deduced amino acid sequence contains two domains with conserved motifs that are implicated in the carbohydrate binding of galectins, (ii) in vitro translation products of galectin-8 cDNA or bacterially expressed recombinant galectin-8 are biologically active and possess sugar binding and hemagglutination activity, and (iii) a protein of the expected size (34 kDa) that binds to lactosyl-Sepharose and reacts with galectin-8-specific antibodies is present in rat liver and comprises approximately 0.025% of the total Triton X-100-soluble hepatic proteins. Overall, galectin-8 is structurally related (34% identity) to galectin-4, a soluble rat galectin with two carbohydrate-binding domains in the same polypeptide chain, joined by a link peptide. Nonetheless, several important features distinguish these two galectins: (i) Northern blot analysis revealed that, unlike galectin-4 that is confined to the intestine and stomach, galectin-8 is expressed in liver, kidney, cardiac muscle, lung, and brain; (ii) unlike galectin-4, but similar to galectins-1 and -2, galectin-8 contains 4 Cys residues; (iii) the link peptide of galectin-8 is unique and bears no similarity to any known protein; (iv) the N-terminal carbohydrate-binding region of galectin-8 contains a unique WG-E-I motif instead of the consensus WG-E-R/K motif implicated as playing an essential role in sugar-binding of all galectins. Together with galectin-4, galectin-8 therefore represents a subfamily of galectins consisting of a tandem repeat of structurally different carbohydrate recognition domains within a single polypeptide chain.
Collapse
Affiliation(s)
- Y R Hadari
- Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel
| | | | | | | | | | | |
Collapse
|
880
|
Dagher SF, Wang JL, Patterson RJ. Identification of galectin-3 as a factor in pre-mRNA splicing. Proc Natl Acad Sci U S A 1995; 92:1213-7. [PMID: 7862663 PMCID: PMC42669 DOI: 10.1073/pnas.92.4.1213] [Citation(s) in RCA: 295] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Galectin-3 (M(r) approximately 35,000) is a galactose/lactose-specific lectin found in association with ribonucleoprotein complexes in many animal cells. Cell-free-splicing assays have been carried out to study the requirement for galectin-3 in RNA processing by HeLa cell nuclear extracts by using 32P-labeled MINX as the pre-mRNA substrate. Addition of saccharides that bind galectin-3 with high affinity inhibited product formation in the splicing assay, while addition of carbohydrates that do not bind to the lectin did not inhibit product formation. Nuclear extracts depleted of galectin-3 by affinity adsorption on a lactose-agarose column were deficient in splicing activity. Extracts subjected to parallel adsorption on control cellobiose-agarose retained splicing activity. The activity of the galectin-3-depleted extract could be reconstituted by the addition of purified recombinant galectin-3, whereas the addition of other lectins, either with a similar saccharide binding specificity (soybean agglutinin) or with a different specificity (wheat germ agglutinin), did not restore splicing activity. The formation of splicing complexes was also sensitive to galectin-3 depletion and reconstitution. Together, these results define a requirement for galectin-3 in pre-mRNA splicing and identify it as a splicing factor.
Collapse
Affiliation(s)
- S F Dagher
- Genetics Program, Michigan State University, East Lansing 48824
| | | | | |
Collapse
|
881
|
Baum LG, Seilhamer JJ, Pang M, Levine WB, Beynon D, Berliner JA. Synthesis of an endogeneous lectin, galectin-1, by human endothelial cells is up-regulated by endothelial cell activation. Glycoconj J 1995; 12:63-8. [PMID: 7795414 DOI: 10.1007/bf00731870] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The pattern of expression of an endogenous lectin, galectin-1, was examined in human lymphoid tissue. Galectin-1 was detected in the endothelial cells lining specialized vessels, termed high endothelial venules, in activated lymphoid tissue, but not in a resting lymph node. Cultured endothelial cells (human aortic and umbilical vein endothelial cells (HAECs and HUVECs)) expressed galectin-1. Activation of the cultured endothelial cells increased the level of galectin-1 expression, as determined by ELISA. Northern blot analysis and high throughput cDNA sequencing. These results suggest that galectin-1 expressed by endothelial cells may bind to and affect the trafficking of cells emigrating from blood into tissues.
Collapse
Affiliation(s)
- L G Baum
- Department of Pathology and Laboratory Medicine, UCLA School of Medicine 90024-1732, USA
| | | | | | | | | | | |
Collapse
|
882
|
Abstract
A melibiose-binding protein was isolated from human spleen by serial affinity chromatography on lactose-, mannose-, and melibiose-Sepharose. The purified protein agglutinated rabbit erythrocytes and re-bound to melibiose, but did not bind to murine nor human laminin. The protein was composed of approximately 58 kDa and 26 kDa polypeptides. The polypeptides were detected in buffy coat cell extracts and they were synthesized in vitro by B lymphoblastoid cells. The polypeptides did not react with anti-galaptin, anti-C-reactive protein, anti-amyloid P, anti-keratin, and anti-rat lung lectin 29 sera. The 58 kDa polypeptide reacted very weakly with anti-core-specific lectin serum and reacted with anti-IgG serum. The data suggest that the major protein isolated is an anti-Ga1 alpha 1-->6 immunoglobulin.
Collapse
Affiliation(s)
- A Sharma
- Department of Gynecologic Oncology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA
| | | | | |
Collapse
|
883
|
Helin J, Maaheimo H, Seppo A, Keane A, Renkonen O. Stepwise transfer of alpha-D-Galp-(1-->3)-beta-D-Galp-(1-->4)-beta-D-GlcpNAc sequences to 3-OH and 6-OH of distal galactose residues in bi-, tri-, and tetra-antennary asialo-glycans of N-linked complex type. Carbohydr Res 1995; 266:191-209. [PMID: 7697655 DOI: 10.1016/0008-6215(94)00272-h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The hydroxyl groups 3 and 6 of distal galactose units in bi-, tri-, and tetra-antennary asialo-glycans of N-linked complex type were substituted stepwise by transferase reactions with the sequence alpha-D-Galp-(1-->3)-beta-D-Galp-(1-->4)-beta-D-GlcpNAc. The products of each transferase reaction were purified chromatographically and the structures were confirmed by 1H NMR spectroscopy. Molecular weights of the final products were determined by matrix-assisted laser-desorption mass spectrometry (MALDI-MS).
Collapse
Affiliation(s)
- J Helin
- Institute of Biotechnology, University of Helsinki, Finland
| | | | | | | | | |
Collapse
|
884
|
Chapter 3 3D Structure 1. The Structural Features of Protein-Carbohydrate Interactions Revealed by X-Ray Crystallography. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/s0167-7306(08)60586-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|
885
|
Bourne Y, Bolgiano B, Liao DI, Strecker G, Cantau P, Herzberg O, Feizi T, Cambillau C. Crosslinking of mammalian lectin (galectin-1) by complex biantennary saccharides. NATURE STRUCTURAL BIOLOGY 1994; 1:863-70. [PMID: 7773775 DOI: 10.1038/nsb1294-863] [Citation(s) in RCA: 174] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Galectins are beta-galactoside-binding proteins that occur intra- and extracellularly in many animal tissues. They have been proposed to form networks of glycoconjugates on the cell surface, where they may modulate various cell response pathways such as growth, activation and adhesion. The high resolution X-ray crystallographic analyses of three crystal forms of bovine galectin-1 in complex with biantennary saccharides of N-acetyllactosamine type reveal infinite chains of lectin dimers cross-linked through N-acetyllactosamine units located at the end of the oligosaccharide antenna. The oligosaccharide adopts a different low energy conformation in each of the three crystal forms.
Collapse
Affiliation(s)
- Y Bourne
- Laboratoire de Cristallographie et de Cristallisation des Macromolécules Biologiques, CNRS URA 1296, Secteur-Nord, Marseille, France
| | | | | | | | | | | | | | | |
Collapse
|
886
|
Inohara H, Raz A. Effects of natural complex carbohydrate (citrus pectin) on murine melanoma cell properties related to galectin-3 functions. Glycoconj J 1994; 11:527-32. [PMID: 7696855 DOI: 10.1007/bf00731303] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Citrus pectin (CP) and pH-modified citrus pectin (MCP) are highly branched and non-branched complex polysaccharides, respectively, rich in galactoside residues, capable of combining with the carbohydrate-binding domain of galectin-3. We reported previously that intravenous injection of B16-F1 murine melanoma cells with CP or MCP into syngeneic mice resulted in a significant increase or decrease of lung colonization, respectively (Platt D, Raz A (1992) J Natl Cancer Inst 84:438-42). Here we studied the effects of these polysaccharides on cell-cell and cell-matrix interactions mediated by carbohydrate-recognition. MCP, but not CP, inhibited B16-F1 melanoma cells adhesion to laminin and asialofetuin-induced homotypic aggregation. Both polysaccharides inhibited anchorage-independent growth of B16-F1 cells in semisolid medium, i.e. agarose. These results indicate that carbohydrate-recognition by cell surface galectin-3 may be involved in cell-extracellular matrix interaction and play a role in anchorage-independent growth as well as the in vivo embolization of tumour cells.
Collapse
Affiliation(s)
- H Inohara
- Cancer Metastasis Program, Michigan Cancer Foundation, Detroit 48201
| | | |
Collapse
|
887
|
Ochieng J, Fridman R, Nangia-Makker P, Kleiner DE, Liotta LA, Stetler-Stevenson WG, Raz A. Galectin-3 is a novel substrate for human matrix metalloproteinases-2 and -9. Biochemistry 1994; 33:14109-14. [PMID: 7947821 DOI: 10.1021/bi00251a020] [Citation(s) in RCA: 191] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The primary structure of galectin-3, a approximately 30 kDa galactoside-binding protein (aka CBP-35, mL-34, hL-31, L-29, Mac-2, and epsilon BP), reveals two structural domains: an amino-terminal domain consists of a Pro-Gly-rich motif, and a globular carboxyl-terminal domain containing a carbohydrate-binding site. In this study, we report that the amino-terminal domain of galectin-3 contains a cleavage site for two members of the matrix metalloproteinase family of enzymes: the 72 kDa (gelatinase A, MMP-2) and the 92 kDa (gelatinase B, MMP-9) proteinases. The major cleavage site for the gelatinases in galectin-3 is at the Ala62-Tyr63 bond, and its hydrolysis by these enzymes was inhibited by TIMP-2. Cell-surface expression of galectin-3 was reduced following treatment of viable T47D human breast carcinoma cells with gelatinase A. These results suggest that galectin-3 may be a substrate for gelatinases and that its degradation may play a role in modulating the biological activities of galectin-3.
Collapse
Affiliation(s)
- J Ochieng
- Metastasis Research Program, Michigan Cancer Foundation, Detroit 48201
| | | | | | | | | | | | | |
Collapse
|
888
|
Hirabayashi J, Kasai K. Further evidence by site-directed mutagenesis that conserved hydrophilic residues form a carbohydrate-binding site of human galectin-1. Glycoconj J 1994; 11:437-42. [PMID: 7535135 DOI: 10.1007/bf00731280] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To identify critical amino acid residues for carbohydrate binding of galectins (soluble beta-galactoside-binding lectins found in the animal kingdom). site-directed mutagenesis was performed on human galectin-1. On the basis of the previous results (Hirabayashi and Kasai (1992) J Biol Chem 266:23648-53), more systematic mutagenesis experiments were performed in order to confirm the concept that conserved hydrophilic residues play a central role. When a homologous substitution was made for highly conserved His44, Arg48 or Asn61, the resultant mutant (H44Q, R48H or N61D, respectively) almost completely lacked carbohydrate-binding ability, as found previously for Asn46, Glu71 and Arg73 mutants. This suggests these six hydrophilic residues are essential. On the other hand, when less conserved Lys63, Arg111 or Asp125 were substituted, the resultant mutant (K63H, R111H or D125E, respectively) retained almost the same affinities to asialofetuin and lactose as the wild-type galectin. Therefore, none of these residues is directly involved in the binding. These results, together with the previous observation that the above six essential residues are all encoded in the largest exon of the gene and are located close to each other in the central, most hydrophilic region of the protein, suggest that the residues form a carbohydrate-binding site of galectin.
Collapse
Affiliation(s)
- J Hirabayashi
- Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Kanagawa, Japan
| | | |
Collapse
|
889
|
Lotan R, Belloni PN, Tressler RJ, Lotan D, Xu XC, Nicolson GL. Expression of galectins on microvessel endothelial cells and their involvement in tumour cell adhesion. Glycoconj J 1994; 11:462-8. [PMID: 7696849 DOI: 10.1007/bf00731282] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Lactoside-binding lectins (galectins) with molecular weights of about 14.5 kDa (galectin-1) and 29-35 kDa (galectin-3) bind preferentially to polylactosaminoglycan-containing glycoconjugates and have been found on the surface of tumour cells and implicated in cell-cell and cell-extracellular matrix adhesion and metastasis. We have demonstrated by immunoblotting that both galectin-1 and galectin-3 are present in extracts of endothelial cells cultured from bovine aorta, rat lung, mouse lung and mouse brain microvessels, whereas mouse hepatic sinusoidal endothelial cells expressed primarily galectin-1. These galectins were also localized by indirect immunofluorescent labelling on the surface of the different endothelial cells in culture and by immunohistochemical staining in human tissues in vivo. Anti-galectin-1 antibodies inhibited the adhesion of liver-preferring murine RAW117-H10 large-cell lymphoma cells to hepatic sinusoidal endothelial cells or lung microvessel endothelial cells in vitro. The data indicate that galectin-1 is expressed on the extracellular surface of endothelial cells and can mediate in part the adhesion of RAW117-H10 cells to liver microvessel endothelial cells.
Collapse
MESH Headings
- Animals
- Antigens, Differentiation/metabolism
- Cattle
- Cell Adhesion
- Cell Membrane/metabolism
- Cells, Cultured
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Galectin 1
- Galectin 3
- Hemagglutinins/immunology
- Hemagglutinins/metabolism
- Lectins/immunology
- Lectins/metabolism
- Lymphoma, Large B-Cell, Diffuse/metabolism
- Lymphoma, Large B-Cell, Diffuse/pathology
- Mice
- Mice, Inbred BALB C
- Rats
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- R Lotan
- Department of Tumor Biology, University of Texas, M.D. Anderson Cancer Center, Houston 77030
| | | | | | | | | | | |
Collapse
|
890
|
|
891
|
Voss PG, Tsay YG, Wang JL. Galectin-3: differential accumulation of distinct mRNAs in serum-stimulated mouse 3T3 fibroblasts. Glycoconj J 1994; 11:353-62. [PMID: 7873931 DOI: 10.1007/bf00731209] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The murine Galectin-3 gene spans approximately 12 kb of DNA and contains six exons, with the translation initiation codon located in exon II. On the basis of restriction mapping and sequence analysis of the DNA upstream of exon II, primer extension assays, rapid amplification of cDNA ends, and ribonuclease protection assays were designed and carried out to determine the initiation site of transcription and the sequence of exon I. The results revealed at least two transcription initiation sites (alpha and delta), each of which appears to be specifically associated with the use of alternative donor splice sites, resulting in distinct mRNA species. Type I message initiates at transcription start site delta, uses splice donor site No. 2, retaining a 27 bp sequence, whereas type II message initiates at transcription start site alpha, uses splice donor site No. 1, resulting in the loss of the 27 bp sequence. Primer extension assays carried out with mRNA isolated from 3T3 fibroblasts at various times after serum stimulation indicate that while the type II message varies in level only a little over the first 20 h, there is dramatic accumulation of the type I message, which peaks at 16 h post mitogen addition.
Collapse
Affiliation(s)
- P G Voss
- Department of Biochemistry, Michigan State University, East Lansing 48824
| | | | | |
Collapse
|
892
|
Barondes S, Cooper D, Gitt M, Leffler H. Galectins. Structure and function of a large family of animal lectins. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)31891-4] [Citation(s) in RCA: 1041] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
893
|
Solís D, Jiménez-Barbero J, Martín-Lomas M, Díaz-Mauriño T. Probing hydrogen-bonding interactions of bovine heart galectin-1 and methyl beta-lactoside by use of engineered ligands. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 223:107-14. [PMID: 8033884 DOI: 10.1111/j.1432-1033.1994.tb18971.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The binding of different synthetic monodeoxy, O-methyl and fluorodeoxy derivatives of methyl beta-lactoside to galectin-1 from bovine heart has been studied to probe the role of hydrogen bonding in the recognition and binding. The energetic contributions of the hydroxyl groups of methyl beta-lactoside directly involved in the interaction have been estimated and the nature of the protein residues involved has been predicted on the basis of the free energy data. Interpretations of the results have been sustained by molecular modeling of the three-dimensional structure of the sugars in solution. One side of the disaccharide molecule is not involved (HO-6 and HO-2') or only marginally involved (HO-3') in hydrogen bonding. Moreover, O-methylation at these positions causes an enhancement of the binding, suggesting favourable interactions of the methyl groups which may come into contact with hydrophobic residues at the periphery of the combining site. Hydrogen-bonding interactions are almost exclusively restricted to the other side of the molecule: the C-4' and C-6' hydroxyl groups act as donors of the strongest hydrogen bonds to charged groups of the lectin, while the C-3 hydroxyl group participates in a strong hydrogen bond with a neutral group. The results also suggest that the N-acetyl NH group in N-acetyllactosamine, as well as the hydroxyl group at position C-2 in methyl beta-lactoside, are involved in a polar interaction with neutral groups of the combining site. This hydrogen-bonding pattern contrasts markedly with that previously reported for the two galactose-specific Ricinus communis lectins. The recognition of different epitopes of the same basic structure underlies the differences in the oligosaccharide-binding specificities of galectin-1 and the R. communis lectins.
Collapse
Affiliation(s)
- D Solís
- Instituto de Química Física Rocasolano, Consejo Superior de Investigaciones Cientificas, Madrid, Spain
| | | | | | | |
Collapse
|
894
|
Feizi T, Solomon JC, Yuen CT, Jeng KC, Frigeri LG, Hsu DK, Liu FT. The adhesive specificity of the soluble human lectin, IgE-binding protein, toward lipid-linked oligosaccharides. Presence of the blood group A, B, B-like, and H monosaccharides confers a binding activity to tetrasaccharide (lacto-N-tetraose and lacto-N-neotetraose) backbones. Biochemistry 1994; 33:6342-9. [PMID: 8193150 DOI: 10.1021/bi00186a038] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The immunoglobulin E-binding protein, epsilon BP (also known as CBP35, Mac-2, L-34, and L-29), is a beta-galactoside-binding protein of approximately 30 kDa and a member of the animal lectin family termed S-type or S-Lac. Multiple biological activities have been attributed to this lectin such as mediation of IgE binding to the surface of Langerhans cells and activation of mast cells through binding to the high affinity IgE receptor. In order to better understand the cell-binding activity and the proposed role for epsilon BP as a biological response modifier, we have studied the specificity of binding of the radioiodinated epsilon BP to a series of lipid-linked, structurally defined oligosaccharide sequences of the lacto/neolacto family. The results show that the minimum lipid-linked oligosaccharides that can support epsilon BP binding are pentasaccharides of the lacto/neolacto series and that the lectin binds more strongly to oligosaccharides of this family that bear the blood group A, B, or B-like determinants than to those bearing blood group H. This preferential binding of epsilon BP is also manifest with whole cells, as erythrocytes of blood groups A and B are more strongly bound by epsilon BP than those of blood group O. Blood group Le(a) and Le(x) sequences are not bound by the lectin.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- T Feizi
- Glycoconjugates Section, MRC Clinical Research Centre, Harrow, Middlesex, U.K
| | | | | | | | | | | | | |
Collapse
|
895
|
Mandrell RE, Apicella MA, Lindstedt R, Leffler H. Possible interaction between animal lectins and bacterial carbohydrates. Methods Enzymol 1994; 236:231-54. [PMID: 7968613 DOI: 10.1016/0076-6879(94)36019-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- R E Mandrell
- Oak Research Institute, Oakland Childrens Hospital, California 94609
| | | | | | | |
Collapse
|
896
|
Bose KS, Sarma RH, Geng S, Geng S, Wei H, Chen G, Li X, Wang L, Wang R, Peng H, Han G, Shen B, Li Y. Delineation of the intimate details of the backbone conformation of pyridine nucleotide coenzymes in aqueous solution. Biochem Biophys Res Commun 1976; 48:670-7. [PMID: 2 DOI: 10.1016/j.molimm.2010.11.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 11/15/2010] [Accepted: 11/16/2010] [Indexed: 12/21/2022]
|