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1.
Int J Tuberc Lung Dis ; 16(3): 319-26, 2012.
Article in English | MEDLINE | ID: mdl-22640444

ABSTRACT

OBJECTIVE: To characterise and classify clinical isolates collected from tuberculosis (TB) patients in rural Bangladesh and to investigate the mode of transmission. DESIGN: An epidemiological study using a combination of conventional and molecular methods was performed in a rural population of Bangladesh. A total of 168 clinical isolates were collected from TB patients. Deletion analysis, used for rapid differentiation of members of the Mycobacterium tuberculosis complex, spoligotyping and variable number tandem repeats of mycobacterial interspersed repetitive units (VNTR-MIRU) typing were used. RESULTS: Deletion analysis identified all isolates as M. tuberculosis and further divided them into 109 strains (65%) carrying the M. tuberculosis deletion region 1 (TbD1-intact or 'ancestral' strains) and 59 strains (35%) lacking this region (TbD1 or 'modern' strains). MIRU analyses showed that 149 strains (89%) had unique patterns, whereas 19 strains (11%) clustered into eight groups. The largest cluster comprised five TbD1 strains of the Beijing type. The rate of recent transmission was estimated to be 6.5%. CONCLUSIONS: Our results suggest that TB in rural Bangladesh is caused primarily by reactivation of latent infections involving TbD1 intact strains, overlaid with the recent emergence of Beijing strain clusters that include multidrug-resistant isolates.


Subject(s)
Molecular Epidemiology/methods , Mycobacterium tuberculosis/isolation & purification , Tuberculosis/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Bacterial Typing Techniques/methods , Bangladesh/epidemiology , Cluster Analysis , Female , Humans , Latent Tuberculosis/epidemiology , Latent Tuberculosis/microbiology , Latent Tuberculosis/transmission , Male , Middle Aged , Mycobacterium tuberculosis/genetics , Rural Population , Tandem Repeat Sequences , Tuberculosis/microbiology , Tuberculosis/transmission , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis, Multidrug-Resistant/transmission , Young Adult
2.
Oncogene ; 27(39): 5233-42, 2008 Sep 04.
Article in English | MEDLINE | ID: mdl-18521086

ABSTRACT

NRIF3 is an estrogen-inducible nuclear receptor coregulator that stimulates estrogen receptor-alpha (ERalpha) transactivation functions and associates with the endogenous ER and its target gene promoter. p21-activated protein kinase 1 (Pak1) phosphorylates ERalpha at Ser305 and this modification is important in ERalpha transactivation function. Although ERalpha transactivation functions are regulated by co-activator activity of NRIF3, it remains unclear whether Pak1 could impact ER functions via a posttranslational modification of NRIF3. Here, we report that Pak1 phosphorylates NRIF3 at Serine28 and that NRIF3 binds to Pak1 in vitro and in vivo. We found that NRIF3 phosphorylation, co-activator activity and association with ERalpha increased following Pak1 phosphorylation of NRIF3's Ser28 and that activated ERalpha-Ser305 and NRIF3-Ser28 cooperatively support transactivation of ERalpha. NRIF3 expression increased significantly in cells with inducible Pak1 expression. We found that NRIF3 and ERalpha interaction, subcellular localization and ERalpha transactivation activity all increased in cells expressing the Pak1 phosphorylation-mimicking mutant NRIF3-Ser28Glu. Consistently, the NRIF3-Ser28Glu mutant exhibited an enhanced recruitment to the endogenous ER target genes and increased expression following estrogen stimulation. Finally, breast cancer cells with stable overexpression of NRIF3 showed increased proliferation and enhanced anchorage-independent growth. These findings suggest that NRIF3-Ser28 is a physiologic target of Pak1 signaling and contributes to the enhanced NRIF3 co-activator activity, leading to coordinated potentiation of ERalpha transactivation, its target gene expression and estrogen responsiveness of breast cancer cells.


Subject(s)
Estrogen Receptor alpha/genetics , Nuclear Proteins/physiology , Serine/metabolism , Transcriptional Activation/physiology , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation , Humans , Nuclear Proteins/metabolism , Phosphorylation , Protein Binding , p21-Activated Kinases/metabolism
3.
Br J Cancer ; 98(6): 1132-40, 2008 Mar 25.
Article in English | MEDLINE | ID: mdl-18283314

ABSTRACT

The ErbB3 binding protein (Ebp1) is a transcriptional corepressor that inhibits the activity of proliferation-associated genes and the growth of human breast cancer cell lines. Treatment of breast cancer cells with the ErbB3 ligand heregulin (HRG) results in increased phosphorylation of Ebp1 and transcriptional repression. The p21-activated serine/threonine kinase 1 (PAK1), which plays an important role in breast cancer progression and resistance to the anti-oestrogen tamoxifen, is also activated by HRG. We therefore examined the ability of PAK1 to phosphorylate and regulate the function of Ebp1. We found that PAK1 phosphorylated Ebp1 in vitro and mapped the phosphorylation site to threonine 261. Both HRG treatment and expression of a constitutively activated PAK1 in MCF-7 breast cancer cells enhanced threonine phosphorylation of Ebp1. In MCF-7 cells, ectopically expressed Ebp1 bound endogenous PAK1 and this association was enhanced by treatment with HRG. Mutation of the PAK1 phosphorylation site to glutamic acid, mimicking a phosphorylated state, completely abrogated the ability of Ebp1 to repress transcription, inhibit growth of breast cancer cell lines and contribute to tamoxifen sensitivity. These studies demonstrate for the first time that Ebp1 is a substrate of PAK1 and the importance of the PAK1 phosphorylation site for the functional activity of Ebp1 in breast cancer cells.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Breast Neoplasms/metabolism , RNA-Binding Proteins/metabolism , p21-Activated Kinases/metabolism , Adaptor Proteins, Signal Transducing/genetics , Cell Proliferation/drug effects , Humans , Mutation , Phosphorylation , Protein Binding , RNA-Binding Proteins/genetics , Substrate Specificity , Tamoxifen/pharmacology , Transfection , Tumor Cells, Cultured
4.
Oncogene ; 25(9): 1311-9, 2006 Mar 02.
Article in English | MEDLINE | ID: mdl-16278681

ABSTRACT

p21-activated protein kinase 1 (Pak1) plays an important role in several cellular processes, including cytoskeleton reorganization, promotion of the cell survival, and the estrogen receptor (ER) signaling. Pak1 expression and activity is deregulated in a number of cancers. Pak1 is activated by a variety of physiological signals; however, less is known about the negative regulators of Pak1. Here, we report a negative regulator of Pak1. By performing a yeast two-hybrid screen of a mammary gland library, we identified cysteine-rich inhibitor of Pak1 (CRIPak) as a novel Pak1-interacting protein. We found that CRIPak is an intronless gene that localized to chromosome 4p16.3. It contains 13 zinc-finger domains and has three trypsin inhibitor-like, cysteine-rich domains and is widely expressed in a number of human cells and tissues. We further found that CRIPak interacted with Pak1 through the N-terminal regulatory domain and inhibited Pak1 kinase in both in vitro and in vivo assays. CRIPak inhibited Pak1-mediated LIM kinase activation and enhancement of ER transactivation. Conversely, selective inhibition of the endogenous CRIPak resulted in an increased Pak1 activity, and consequently, increased cytoskeleton remodeling and Pak1-mediated ER transactivation activity. The hormonal stimulation of cells enhanced CRIPak expression and promoted its colocalization with ER in the nuclear compartment. Our findings suggest that CRIPak is a novel negative regulator of the Pak1 and has a role in the modulation of Pak1-mediated ER transactivation in breast cancer cells.


Subject(s)
Breast Neoplasms/genetics , Carrier Proteins/physiology , Chromosomes, Human, Pair 4 , Protein Serine-Threonine Kinases/biosynthesis , Amino Acid Sequence , Animals , Breast Neoplasms/pathology , COS Cells , Carrier Proteins/genetics , Chlorocebus aethiops , Cytoskeleton/metabolism , Female , Humans , Molecular Sequence Data , Receptors, Estrogen/physiology , Signal Transduction , Two-Hybrid System Techniques , p21-Activated Kinases
5.
J Biol Chem ; 276(8): 5636-42, 2001 Feb 23.
Article in English | MEDLINE | ID: mdl-11104760

ABSTRACT

The epidermal growth factor (EGF) family and its receptors regulate normal and cancerous epithelial cell proliferation, a process that could be suppressed by anti-receptor blocking antibodies. Polypeptide elongation factor-1alpha (EF-1alpha) is a multifunctional protein whose levels are positively correlated with the proliferative state of cells. To identify genes, whose expression may be modulated by anti-receptor blocking antibodies, we performed a differential display screening and isolated differentially expressed cDNAs. Isolates from one clone were 100% identical to human EF-1alpha. Both EGF and heregulin-beta1 (HRG) induced EF-1alpha promoter activity and mRNA and protein expression. Growth factor-mediated EF-1alpha expression was effectively blocked by pretreatment with humanized anti-EGF receptor antibody C225 or anti-human epidermal growth factor receptor-2 (HER2) antibody herceptin. Mutants and pharmacological inhibitors of p38(MAPK) and MEK, but not phosphatidylinositol 3-kinase, suppressed both constitutive and HRG-induced stimulation of EF-1alpha promoter activity in MCF-7 cells. Deletion analysis of the promoter suggested the requirement of the -393 to -204 region for growth factor-mediated transcription of EF-1alpha. Fine mapping and point mutation studies revealed a role of the SP1 site in the observed HRG-mediated regulation of the EF-1alpha promoter. In addition, we also provide new evidence to suggest that HRG stimulation of the EF-1alpha promoter involves increased physical interactions with acetylated histone H3 and histone H4. These results suggest that regulation of EF-1alpha expression by extracellular signals that function through human EGF receptor family members that are widely deregulated in human cancers and that growth factor regulation of EF-1alpha expression involve histone acetylation.


Subject(s)
Antibodies, Blocking/pharmacology , ErbB Receptors/metabolism , Neuregulin-1/metabolism , Peptide Elongation Factor 1/biosynthesis , Acetylation , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal, Humanized , ErbB Receptors/immunology , Gene Expression Regulation , Histones/metabolism , Neuregulin-1/immunology , Promoter Regions, Genetic , Receptor Protein-Tyrosine Kinases/metabolism , Signal Transduction , Sp1 Transcription Factor/metabolism , Trastuzumab
6.
Mol Cell Biol ; 20(23): 9092-101, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11074007

ABSTRACT

Heregulin beta1 (HRG), a combinatorial ligand for human growth factor receptors 3 and 4, is a regulatory polypeptide that promotes the differentiation of mammary epithelial cells into secretory lobuloalveoli. Emerging evidence suggests that the processes of secretory pathways, such as biogenesis and trafficking of vesicles in neurons and adipose cells, are regulated by the Rab family of low-molecular-weight GTPases. In this study, we identified Rab3A as a gene product induced by HRG. Full-length Rab3A was cloned from a mammary gland cDNA library. We demonstrated that HRG stimulation of human breast cancer cells and normal breast epithelial cells induces the expression of Rab3A protein and mRNA in a cycloheximide-independent manner. HRG-mediated induction of Rab3A expression was blocked by an inhibitor of phosphatidylinositol 3-kinase but not by inhibitors of mitogen-activated protein kinases p38(MAPK) and p42/44(MAPK). Human breast epithelial cells also express other components of regulated vesicular traffic, such as rabphilin 3A, Doc2, and syntaxin. Rab3A was predominantly localized in the cytosol, and HRG stimulation of the epithelial cells also raised the level of membrane-bound Rab3A. HRG treatment induced a profound alteration in the cell morphology in which cells displayed neuron-like membrane extensions that contained Rab3A-coated, vesicle-like structures. In addition, HRG also promoted the secretion of cellular proteins from the mammary epithelial cells. The ability of HRG to modify exocytosis was verified by using a growth hormone transient-transfection system. Analysis of mouse mammary gland development revealed the expression of Rab3A in mammary epithelial cells. Furthermore, expression of the HRG transgene in Harderian tumors in mice also enhanced the expression of Rab3A. These observations provide new evidence of the existence of a Rab3A pathway in mammary epithelial cells and suggest that it may play a role in vesicle trafficking and secretion of proteins from epithelial cells in response to stimulation by the HRG expressed within the mammary mesenchyma.


Subject(s)
Breast/metabolism , Epithelial Cells/metabolism , Exocytosis/drug effects , Neuregulin-1/pharmacology , Protein Transport/drug effects , rab3A GTP-Binding Protein/metabolism , Animals , Breast/cytology , Breast Neoplasms , Cell Compartmentation , Cell Membrane/metabolism , Dexamethasone/pharmacology , Female , Gene Expression Regulation , Humans , Insulin/pharmacology , Intracellular Membranes/metabolism , Lactation/physiology , Mammary Glands, Animal/cytology , Mammary Glands, Animal/metabolism , Mice , Prolactin/pharmacology , Signal Transduction , rab3A GTP-Binding Protein/genetics
7.
Cancer Res ; 60(2): 276-81, 2000 Jan 15.
Article in English | MEDLINE | ID: mdl-10667576

ABSTRACT

Heregulin beta1 (HRG), a combinatorial ligand for human epidermal growth factor receptor 3 and human epidermal growth factor receptor 4 receptors, is a regulatory secretory polypeptide with distinct biological effects such as growth stimulation, differentiation, invasiveness, and migration in breast cancer cells. The mechanism underlying the diverse functions of HRG is not well established, but it is believed to be dependent on the induced changes in expression of specific cellular gene products, their modification, or both. The binding of basic leucine zipper transcription factors to the cAMP response element is known to activate a variety of gene products with a role or roles in growth regulation. In the studies presented here, we identified basic leucine zipper activating transcription factor (ATF) 4 as one of the HRG-inducible gene product. We demonstrated that HRG stimulation of human cancer cells induces expression of ATF4 mRNA and protein, ATF4 DNA binding activity, and ATF4 transactivating function. Consistent with its role as a transcriptional activator, HRG-stimulated ATF4 protein stimulated the transcription from an artificial promoter with three tandem ATF sites or from a naturally occurring promoter with ATF4 sites such as E-selectin. We also demonstrated a preferential role of the HRG-stimulated mitogen-activated protein kinase pathway, but not the phosphatidylinositol 3'-kinase pathway, in supporting the observed increase in ATF4 DNA binding activity and transcription from E-selectin promoter in HRG-stimulated cells. Because ATF4 binding sites are present in a variety of growth-regulating cellular genes, these findings suggest that the stimulation of ATF4 expression and its transactivating functions may constitute an important mechanism of HRG-mediated regulation of putative genes with diversified functions. The present study is the first demonstration of regulation of expression and transactivation ability of ATF4 by any polypeptide growth factor.


Subject(s)
Gene Expression Regulation, Neoplastic/drug effects , Neuregulin-1/pharmacology , Transcription Factors/genetics , Transcription Factors/metabolism , Transcriptional Activation/drug effects , Activating Transcription Factor 4 , Breast Neoplasms , Colonic Neoplasms , Female , Humans , Kinetics , Leucine Zippers , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Transcription, Genetic/drug effects , Tumor Cells, Cultured
8.
Cancer Res ; 60(2): 474-80, 2000 Jan 15.
Article in English | MEDLINE | ID: mdl-10667603

ABSTRACT

The exposure of cells to growth factors has been shown to induce cytoskeleton reorganization, leading to stimulation of cell motility and invasion. Heregulin beta1 (HRG), a combinatorial ligand for human epidermal growth factor receptor 3 and human epidermal growth factor receptor 4 receptors, is a regulatory secretory polypeptide with a distinctive function in promoting motility and invasiveness of breast cancer cells. In addition to HRG, motility and invasiveness of tumor cells may also involve up-regulation of expression and function of the autocrine motility factor (AMF). Here we explored the possible involvement of AMF in the motility-promoting action of HRG in the MCF-7 breast cancer cell model system. We report that HRG increases the expression of AMF mRNA by 3-8-fold in an actinomycin D-sensitive manner and does not require de novo protein synthesis. The HRG-induced stimulation of AMF expression was inhibited by specific inhibitors of p42/44MAPK and p38MAPK kinases, but not by an inhibitor of the phosphatidylinositol 3'-kinase pathway. Other HRG-responsive human cell lines demonstrated that HRG does indeed significantly up-regulate AMF expression. Furthermore, HRG-stimulated increased motility was partially suppressed by inclusion of an anti-AMF antibody to breast cancer cells, suggesting that a HRG-mediated increase in cell motility may be mediated, at least in part, via induction of AMF. The present study is the first demonstration of AMF regulation by a growth factor and suggests a potential role for AMF in HRG regulation of breast cancer cell motility and a novel function of HRG as a regulator of motility factor expression.


Subject(s)
Gene Expression Regulation/drug effects , Glucose-6-Phosphate Isomerase/genetics , Neuregulin-1/pharmacology , Transcription, Genetic/drug effects , Actins/genetics , Actins/metabolism , Amino Acid Sequence , Antibodies , Breast Neoplasms , Cell Movement/drug effects , Colonic Neoplasms , Colorectal Neoplasms , Female , Glucose-6-Phosphate Isomerase/analysis , Glucose-6-Phosphate Isomerase/biosynthesis , Humans , Molecular Sequence Data , Peptide Fragments/immunology , RNA, Messenger/genetics , Tumor Cells, Cultured
9.
J Biochem ; 123(6): 1127-36, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9604002

ABSTRACT

The removal of N-terminally located clusters of basic amino acids (N-tail) or C-terminally located clusters of basic amino acids (C-tail) from the midkine (MK) molecule severely reduced its neurite-promoting activity. However, experiments involving chemically synthesized MK derivatives revealed that the roles of the N-tail and C-tail were mostly indirect ones, i.e. they probably maintain the steric arrangements of the N-terminal and C-terminal halves. In particular, the C-domain, which is the C-terminal half devoid of the C-tail, retained considerable neurite-promoting activity when it was uniformly coated on a dish. The removal of the N-tail or C-tail also reduced the enhancing activity of plasminogen activator (PA) in aortic endothelial cells, although the effect was lower. There are two heparin-binding sites in the C-domain, Clusters I and II. A mutation in Cluster I [R78-->Q] affected the PA-enhancing activity only slightly, and a mutation in Cluster II [K83K84-->QQ] abolished the activity, while both mutations are known to reduce the neurite-promoting activity moderately. Therefore, the two heparin-binding sites in the C-domain play different roles in these two activities. Indeed, heparin exhibited different effects on these two activities. We also observed that intact MK was required for ordered neurite-promotion along the path of MK; one possible interpretation of this is that the N-terminal half is necessary for the stability of the molecule. Furthermore, K76 and K99 were found to be required for the secretion of MK; i.e. mutants in which one of these K residues was changed to Q were produced in the host cells, but not found in the medium.


Subject(s)
Carrier Proteins/genetics , Carrier Proteins/pharmacology , Cytokines , Nerve Growth Factors/genetics , Nerve Growth Factors/pharmacology , Plasminogen Activators/genetics , Plasminogen Activators/pharmacology , Plasminogen/metabolism , Amino Acid Substitution , Amino Acids/genetics , Animals , Carrier Proteins/metabolism , Cells, Cultured , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Humans , Mice , Midkine , Mutation , Nerve Growth Factors/metabolism , Neurites/drug effects , Neurites/ultrastructure , Plasminogen/drug effects , Plasminogen Activators/metabolism
10.
Cell Struct Funct ; 22(4): 477-85, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9368721

ABSTRACT

We have isolated cDNA clones from a mouse embryonic head cDNA library that encode one member of the Eph/Eck family of receptor tyrosine kinases (RTKs), Ebk/MDK1. Among the 10 clones, two showed full-length type comprising extracellular, transmembrane and intracellular kinase domains. Two of them were modified just after the transmembrane domain and stop codon appeared before completing the kinase domain. This truncated form also had a deletion of five amino acids at the extracellular domain, indicating that it is a novel variant of Ebk/MDK1. RNase protection assay showed that this truncated deleted type, named Ebk-td1, is present in the head of embryos, although the amount is less compared to that of the full-length type having a deletion of four amino acids. Considering the source and expression of Ebk/MDK1 mRNAs, they may have an important role, accompanied with a possible regulatory role of the truncated variant, during neural development and/or in embryogenesis.


Subject(s)
Brain/metabolism , Receptor Protein-Tyrosine Kinases/genetics , Amino Acid Sequence , Animals , Base Sequence , Brain/embryology , Brain Chemistry/genetics , DNA, Complementary , Gene Expression , Gene Library , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Receptor Protein-Tyrosine Kinases/biosynthesis , Sequence Homology, Amino Acid
11.
Biochem Biophys Res Commun ; 228(1): 176-81, 1996 Nov 01.
Article in English | MEDLINE | ID: mdl-8912655

ABSTRACT

When digested with a low concentration of chymotrypsin, midkine (MK) underwent limited proteolysis and produced two fragments with Mr of 11,000 and 6,000 Da. The cleavage site was identified as on the carboxyl side of Phe55. This limited proteolysis was specifically inhibited by heparin, but not by other glycosaminoglycans. Using various heparin-derived oligosaccharides with different chain lengths or chemically desulfated heparin derivatives, it was shown that a minimum of 6 monosaccharide units was necessary for the inhibition, and that sulfonyl groups of the heparin disaccharide unit were required for inhibition. The present study showed that MK consists of two domains, N- and C-domains, and that Phe55 localized to the hinge region is exposed on the surface of the molecule. It was also suggested that the N-domain may function as a stabilizing domain against proteolytic degradation of the C-domain in the intact molecule.


Subject(s)
Carrier Proteins/metabolism , Chymotrypsin/metabolism , Cytokines , Heparin/metabolism , Amino Acid Sequence , Animals , Carrier Proteins/chemistry , Heparin/analogs & derivatives , Heparin/chemistry , Heparin/pharmacology , Mice , Midkine , Molecular Sequence Data , Oligosaccharides/pharmacology , Protein Structure, Tertiary , Sulfates
12.
J Biochem ; 119(6): 1150-6, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8827451

ABSTRACT

By means of a baculovirus expression system, a large amount of mouse midkine (MK) was produced. The protein was purified to homogeneity by heparin-Sepharose column chromatography. The purified protein was of a mature type; the signal peptide was cleaved at the expected site. To examine the neurite-guiding activity of MK, rat embryonic brain cells (embryonic days 17-18) were cultured on plates coated with purified MK in a grid pattern. The cells attached to and extended their neurites along the substrate pattern. This interaction was strongly inhibited by heparin, but not by other glycosaminoglycans. Treatment of the cells with heparitinase was effective for inhibiting their adhesion to the substrate. These data suggest that the heparin-like domain on cell surface heparan sulfate proteoglycan is the primary site for MK binding upon interaction with nerve cells.


Subject(s)
Carrier Proteins/physiology , Cytokines , Amino Acid Sequence , Animals , Baculoviridae/genetics , Baculoviridae/metabolism , Carrier Proteins/biosynthesis , Carrier Proteins/genetics , Cell Adhesion/drug effects , Cell Differentiation/drug effects , Cell Line/metabolism , Cells, Cultured/drug effects , Cerebral Cortex/embryology , Cloning, Molecular , DNA, Complementary/biosynthesis , DNA, Complementary/genetics , Heparin/pharmacology , Heparin Lyase , Insecta , Mice , Midkine , Molecular Sequence Data , Neurites/physiology , Polysaccharide-Lyases/pharmacology , Rats
13.
Biochem Biophys Res Commun ; 220(1): 108-12, 1996 Mar 07.
Article in English | MEDLINE | ID: mdl-8602827

ABSTRACT

Midkine is a heparin binding growth/differentiation factor with neurite promoting activity. We examined inhibitory activities of various heparin derivatives toward interaction of midkine with neurons and elucidated the structural requirements of the heparin-like domain necessary for the interaction. All of the three sulfate groups in the heparin disaccharide unit (6-O-sulfate, 2-O-sulfate and N-sulfate) were necessary for full inhibitory activity. Among these, the N-sulfate group was critically important. The minimum size with inhibitory activity was approximately 7,000 Da. Thus, the highly sulfated region in cell surface heparan sulfate proteoglycan is required for neurons to interact with midkine.


Subject(s)
Carrier Proteins/chemistry , Carrier Proteins/pharmacology , Cytokines , Heparin/chemistry , Heparin/pharmacology , Animals , Binding Sites , Carrier Proteins/metabolism , Cell Adhesion/drug effects , Cells, Cultured , Heparin/metabolism , Heparitin Sulfate/chemistry , Mice , Midkine , Molecular Structure , Molecular Weight , Neurons/cytology , Neurons/drug effects , Neurons/metabolism , Rats , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology , Structure-Activity Relationship , Sulfates/chemistry
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