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1.
Sci Rep ; 8(1): 2018, 2018 01 31.
Article in English | MEDLINE | ID: mdl-29386558

ABSTRACT

In this study we test whether principal components of the strain rate and stress tensors align within Switzerland. We find that 1) Helvetic Nappes line (HNL) is the relevant tectonic boundary to define different domains of crustal stress/surface strain rates orientations and 2) orientations of T- axes (of moment tensor solutions) and long-term asthenosphere cumulative finite strain (from SKS shear wave splitting) are consistent at the scale of the Alpine arc in Switzerland. At a more local scale, we find that seismic activity and surface deformation are in agreement but in three regions (Basel, Swiss Jura and Ticino); possibly because of the low levels of deformation and/or seismicity. In the Basel area, deep seismicity exists while surface deformation is absent. In the Ticino and the Swiss Jura, where seismic activity is close to absent, surface deformation is detected at a level of ~2 10-8/yr (~6.3 10-16/s).

2.
Ann Dermatol Venereol ; 140(4): 287-90, 2013 Apr.
Article in French | MEDLINE | ID: mdl-23567231

ABSTRACT

BACKGROUND: Mycetoma is a chronic skin and soft tissue infection encountered in the dry tropical regions and are caused by fungi (eumycetoma) or bacteria (actinomycetoma). PATIENTS AND METHODS: A 25-year-old man consulted at the hospital on Mayotte Island for a left knee injury sustained 10 years earlier in a motorcycle accident with broken skin occurring in Anjouan in the Comoro Islands. Clinical and histological diagnosis of mycetoma was made, and in the absence of microbiological diagnosis, empirical antifungal therapy was initiated. Given the poor outcome, new biopsies were performed and resulted in the identification of Nocardia otitidiscaviarum. More than 1 year later, the patient had fully recovered and after administration of several and extended antibiotic courses including cotrimoxazole and linezolid. DISCUSSION: Bacterial mycetomas are usually described in semi-arid regions and the occurrence of this disease is unexpected in humid tropical areas such as the Comoro Islands. N. otitidiscaviarum is rarely involved in this infection, particularly in Africa.


Subject(s)
Knee/microbiology , Mycetoma/diagnosis , Nocardia/isolation & purification , Accidents, Traffic , Acetamides/therapeutic use , Adult , Anti-Infective Agents/therapeutic use , Comoros , Humans , Knee Injuries/complications , Linezolid , Male , Mycetoma/drug therapy , Oxazolidinones/therapeutic use , Skin/injuries , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Tropical Climate
3.
Bull Soc Pathol Exot ; 101(4): 316-22, 2008 Oct.
Article in French | MEDLINE | ID: mdl-18956814

ABSTRACT

Mayotte is a French territory island, part of the Comoros Archipelago in the Indian Ocean with 200,000 inhabitants. The tuberculosis control program started in 1976, although available epidemiological data remains incomplete. We conducted a retrospective hospital-based survey in 202 outpatients and hospital medical records from the Hospital Centre of the main city to contribute to the epidemiological evaluation of tuberculosis patterns. The tuberculosis frequency remains unchanged since 2000. It affects a young population partly coming from the other neighbouring Comoro Islands (69%) with illegal immigrate status (53% in 2004). The systematic diagnostic screening efficiency of the condition appears marginal. Pulmonary involvement is the most frequent clinical manifestation (78%), although severe extrapulmonary manifestations are not exceptional. Co-infection with HIV and multi resistance to antituberculosis agents are not frequent. Up to 60% of cases have been proven to be bacteriologically linked. The notification rate remains critically low with an estimate of 39% of notifications to the local sanitary authorities in charge of secondary cases screening. The case coverage seems limited both by low socio-economical status and poor health facility accessibility The loss of follow up is dramatically high, 41% on the overall period, and up to 51% in 2004. Our results make mandatory the reinforcement of a tuberculosis survey and control involvement within the context of this French territory. Screening, care and follow up are to be implemented particularly for vulnerable and precarious groups and for patients.


Subject(s)
Tuberculosis/epidemiology , Tuberculosis/pathology , Comoros/epidemiology , Humans , Incidence , Registries , Retrospective Studies , Socioeconomic Factors , Tuberculosis/complications , Tuberculosis/economics
4.
IUBMB Life ; 55(3): 171-3, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12822896
5.
Mol Biotechnol ; 22(1): 33-49, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12353913

ABSTRACT

There are currently 25 known vertebrate matrix metalloproteinases (MMPs) and 4 tissue inhibitors of metalloproteinases (TIMPs). This article reviews these proteases from an historical perspective in terms of who discovered each protein, when the sequence was established, when action on protein substrates was demonstrated, and what names have been used. A similar approach is taken for the TIMPS, and their multiple functions in addition to protease inhibition are emphasized. MMPs from invertebrates, plants, and bacteria are also discussed. This review is an outgrowth and update of a chapter by the same name originally published in Matrix Metalloproteinase Protocols, pp. 1-23, edited by I. M. Clark and published by Humana Press in 2001.


Subject(s)
Matrix Metalloproteinases/history , Tissue Inhibitor of Metalloproteinases/history , Animals , Enzyme Inhibitors , History, 20th Century , History, 21st Century , Internet , Matrix Metalloproteinases/chemistry , Matrix Metalloproteinases/classification , Matrix Metalloproteinases/genetics , Species Specificity , Substrate Specificity , Tissue Inhibitor of Metalloproteinases/chemistry , Tissue Inhibitor of Metalloproteinases/classification , Tissue Inhibitor of Metalloproteinases/genetics
6.
Biotechniques ; 33(2): 420-3, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12188195

ABSTRACT

High-throughput genomic approaches to gene function or target identification have led to the development and implementation of the 96-well format for many standard molecular biology manipulations. The apparatus described here, a Multichannel Plating Unit, is designed to plate out individual cultures efficientlyfrom standard 96-well culture blocks. Following transformation, aliquots of culture are loaded onto sterile beads that are rolled along individual channels of agar media. After the beads traverse the channel, they drop into the exit alley for disposal via an exit pore. The apparatus presented has 12 individual lanes, and the spacing is compatible with a standard 12-channel pipettor Thus, the unit allows for the rapid plating of 12 individual cultures at a time. For one 96-well block of transformants, this method reduces the labeling and plating effort from 96 culture dishes that are spread individually to eight multichannel plates. The savings in time, materials, and storage space is significant


Subject(s)
Bacteria/genetics , Bacteriological Techniques/instrumentation , Bacteriological Techniques/methods , Bacteria/classification , Escherichia coli , Quality Control , Sequence Analysis, DNA/instrumentation , Transformation, Bacterial
7.
Eur J Obstet Gynecol Reprod Biol ; 102(2): 195-8, 2002 May 10.
Article in English | MEDLINE | ID: mdl-11950490

ABSTRACT

OBJECTIVE: The assessment of relationship between pubocervical collagen content and clinical results of surgical treatment of genuine stress urinary incontinence (GSUI) in women. METHODS: Twenty-four women treated for genuine stress urinary incontinence were included into the study. All women underwent the same surgical procedure. The samples of pubocervical fascia were taken at the time of surgery. The contents of acid soluble, pepsin soluble, insoluble fraction of collagen, total collagen and collagen crosslinks were measured. The study of pubocervical fascia collagen metabolism included also estimation of collagenase activity. At follow-up done 5 years following surgery, 20 patients reported symptoms of GSUI (study group). Four women were still without symptoms of urine leakage (control group). RESULTS: The biochemical parameters of pubocervical fascia did not show, statistically significant differences between compared groups. CONCLUSION: The pubocervical fascia collagen metabolism does not have impact on the results of anti-incontinence surgery.


Subject(s)
Collagen/analysis , Connective Tissue/chemistry , Fascia/chemistry , Treatment Failure , Urinary Incontinence, Stress/surgery , Cervix Uteri , Female , Humans , Pubic Bone , Risk Factors , Urinary Bladder/surgery
8.
Genes Dev ; 16(3): 307-23, 2002 Feb 01.
Article in English | MEDLINE | ID: mdl-11825873

ABSTRACT

CD44 is a facultative proteoglycan implicated in cell adhesion and trafficking, as well as in tumor survival and progression. We demonstrate here that CD44 heparan sulfate proteoglycan (CD44HSPG) recruits proteolytically active matrix metalloproteinase 7 (matrilysin, MMP-7) and heparin-binding epidermal growth factor precursor (pro-HB-EGF) to form a complex on the surface of tumor cell lines, postpartum uterine and lactating mammary gland epithelium, and uterine smooth muscle. The HB-EGF precursor within this complex is processed by MMP-7, and the resulting mature HB-EGF engages and activates its receptor, ErbB4, leading to, among other events, cell survival. In CD44(-/-) mice, postpartum uterine involution is accelerated and maintenance of lactation is impaired. In both uterine and mammary epithelia of these mice, MMP-7 localization is altered and pro-HB-EGF processing as well as ErbB4 activation are decreased. Our observations provide a mechanism for the assembly and function of a cell surface complex composed of CD44HSPG, MMP 7, HB-EGF, and ErbB4 that may play an important role in the regulation of physiological tissue remodeling.


Subject(s)
Breast/physiology , ErbB Receptors/metabolism , Hyaluronan Receptors/physiology , Matrix Metalloproteinase 7/metabolism , Receptors, Cell Surface/metabolism , Uterus/physiology , Animals , Blotting, Western , Cell Division , Cell Survival , Cells, Cultured , Female , Heparin-binding EGF-like Growth Factor , Intercellular Signaling Peptides and Proteins , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Mice, Knockout , Microscopy, Confocal , Phosphorylation , Postpartum Period , Precipitin Tests , Protein Isoforms/metabolism , Receptor, ErbB-4
10.
Fungal Genet Biol ; 33(2): 137-43, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11456466

ABSTRACT

A bacterial artificial chromosome (BAC) clone containing 110,467 bp of genomic DNA from Magnaporthe grisea was sequenced, annotated, and compared to the genomes of Neurospora crassa, Candida albicans, and Saccharomyces cerevisiae. Twenty-six open reading frames (ORFs), involved in multiple biochemical pathways, were identified in the BAC sequence. A region of 53 kb, containing 18 of the 26 ORFs, was found to be syntenic to a portion of the N. crassa genome. Subregions of complete colinearity as well as interrupted colinearity were present. No synteny was evident with either C. albicans or S. cerevisiae. The identification of syntenic regions containing highly conserved genes across two genera that have been evolutionarily separated for approximately 200 million years elicits many biological questions as to the function and identity of these genes.


Subject(s)
Magnaporthe/genetics , Neurospora crassa/genetics , Synteny , Candida albicans/genetics , Chromosomes, Artificial, Bacterial , Cloning, Molecular , DNA Transposable Elements , DNA, Fungal , Genetic Linkage , Genome, Fungal , Open Reading Frames , Saccharomyces cerevisiae/genetics , Sequence Analysis, DNA , Sequence Homology
11.
Anal Biochem ; 293(1): 38-42, 2001 Jun 01.
Article in English | MEDLINE | ID: mdl-11373076

ABSTRACT

Unlike the gelatinases (MMP-2 and -9), matrilysin (MMP-7) and collagenases (MMP-1 and -13) are difficult to detect at low levels in conventional casein or gelatin zymography. In this report, heparin was used to enhance the zymographic assays for MMP-7, -1, and -13. With the addition of heparin to the enzyme sample, MMP-7 can be detected at a level of 30 pg in transferrin zymography and MMP-1 and -13 can be detected at a level of 0.2 ng in gelatin zymography. Carboxymethylated transferrin is used instead of casein as a substrate for assaying rat MMP-7. This substrate does not require a prerun step or substrate cross-linking to give uniform staining and clear band formation. It is necessary for heparin to run to the same region of the gel as the enzyme to produce its enhancing effect. For MMP-7 movement of heparin and enzyme is almost equal; for the collagenases it is necessary to add heparin to each well after the electrophoretic run is underway. Possible mechanisms of activity enhancement are discussed.


Subject(s)
Collagenases/analysis , Heparin/pharmacology , Matrix Metalloproteinase 7/analysis , Animals , Cattle , Collagenases/metabolism , Electrophoresis, Polyacrylamide Gel , Enzyme Activation , Escherichia coli/enzymology , Gelatinases/analysis , Gelatinases/metabolism , Humans , Matrix Metalloproteinase 7/metabolism , Rats , Transferrin/metabolism
12.
Proc Natl Acad Sci U S A ; 98(9): 5110-5, 2001 Apr 24.
Article in English | MEDLINE | ID: mdl-11296265

ABSTRACT

Filamentous fungi are a large group of diverse and economically important microorganisms. Large-scale gene disruption strategies developed in budding yeast are not applicable to these organisms because of their larger genomes and lower rate of targeted integration (TI) during transformation. We developed transposon-arrayed gene knockouts (TAGKO) to discover genes and simultaneously create gene disruption cassettes for subsequent transformation and mutant analysis. Transposons carrying a bacterial and fungal drug resistance marker are used to mutagenize individual cosmids or entire libraries in vitro. Cosmids are annotated by DNA sequence analysis at the transposon insertion sites, and cosmid inserts are liberated to direct insertional mutagenesis events in the genome. Based on saturation analysis of a cosmid insert and insertions in a fungal cosmid library, we show that TAGKO can be used to rapidly identify and mutate genes. We further show that insertions can create alterations in gene expression, and we have used this approach to investigate an amino acid oxidation pathway in two important fungal phytopathogens.


Subject(s)
Ascomycota/genetics , Genes, Fungal/genetics , Madurella/genetics , Alleles , Cloning, Molecular , Cosmids/genetics , Crops, Agricultural/microbiology , DNA Transposable Elements/genetics , Fungal Proteins/genetics , Fungal Proteins/physiology , Gene Deletion , Gene Expression Regulation, Fungal , Genes, Fungal/physiology , Genomic Library , Mutagenesis, Insertional/genetics , Mutagenesis, Site-Directed/genetics , Phenotype , Reproducibility of Results , Sequence Analysis, DNA , Transformation, Genetic
13.
Biochemistry ; 40(9): 2978-87, 2001 Mar 06.
Article in English | MEDLINE | ID: mdl-11258910

ABSTRACT

Hydroxyproline-rich glycoproteins (HRGPs) are the major proteinaceous components of higher plant walls and the predominant components of the cell wall of the green alga Chlamydomonas reinhardtii. The GP1 protein, an HRGP of the C. reinhardtii wall, is shown to adopt a polyproline II helical configuration and to carry a complex array of arabinogalactoside residues, many branched, which are necessary to stabilize the helical conformation. The deduced GP1 amino acid sequence displays two Ser-Pro-rich domains, one with a repeating (SP)(x)() motif and the other with a repeating (PPSPX)(x)() motif. A second cloned gene a2 also carries the PPSPX repeat, defining a novel gene family in this lineage. The SP-repeat domains of GP1 form a 100-nm shaft with a flexible kink 28 nm from the head. The gp1 gene encodes a PPPPPRPPFPANTPM sequence at the calculated kink position, generating the proposal that this insert interrupts the PPII helix, with the resultant kink exposing amino acids necessary for GP1 to bind to partner molecules. It is proposed that similar kinks in the higher plant HRGPs called extensins may play a comparable role in wall assembly.


Subject(s)
Glycoproteins/metabolism , Hydroxyproline/metabolism , Peptides/metabolism , Plant Proteins/metabolism , Amino Acid Motifs , Amino Acid Sequence , Animals , Base Sequence , Carbohydrate Conformation , Carbohydrates/analysis , Chlamydomonas reinhardtii/chemistry , Chlamydomonas reinhardtii/genetics , Cloning, Molecular , Genes, Plant , Glycoproteins/chemistry , Glycoproteins/genetics , Glycosylation , Hydroxyproline/chemistry , Molecular Sequence Data , Peptides/chemistry , Plant Proteins/chemistry , Plant Proteins/genetics , Protein Structure, Secondary , Protein Structure, Tertiary
15.
Osteoarthritis Cartilage ; 9(8): 751-60, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11795995

ABSTRACT

OBJECTIVE: To determine the effect of matrix metalloproteinase (MMP) inhibitors in mono-iodoacetate-induced arthritis in rats. DESIGN: The ability of compounds to inhibit MMPs in vitro was assessed kinetically using a quenched fluorescent substrate. Rats were injected with iodoacetate intraarticularly in one knee joint and damage to the tibial plateau was evaluated from digitized images captured using an image analyser and by histology. Collagenase and gelatinase activity in cartilage from iodoacetate injected knees were evaluated using(3)H-rat type I collagen and gelatin zymography, respectively. RESULTS: Collagenase and gelatinase activity significantly increased in the knee cartilage of rats injected with iodoacetate with peak activity by day 7. Three MMP inhibitors were examined for their efficacy in the rat iodoacetate-induced arthritis model. Significant (P< 0.05) inhibition of cartilage damage was observed in animals treated orally with 35 mg/kg b.i.d. of the three different MMP inhibitors. Inhibition of cartilage damage by the MMP inhibitors ranged from 36-42%. CONCLUSION: MMP inhibitors are partially protective against cartilage and subchondral bone damage induced by iodoacetate. These results support an important role for MMPs in mediating the joint damage in this model of arthritis.


Subject(s)
Enzyme Inhibitors/therapeutic use , Matrix Metalloproteinase Inhibitors , Osteoarthritis/drug therapy , Animals , Collagenases/metabolism , Electrophoresis, Polyacrylamide Gel/methods , Gelatinases/metabolism , Image Processing, Computer-Assisted/methods , Injections, Intra-Articular , Iodoacetates/administration & dosage , Iodoacetates/adverse effects , Male , Osteoarthritis/chemically induced , Osteoarthritis/pathology , Rats , Rats, Sprague-Dawley , Up-Regulation
16.
Am J Physiol Heart Circ Physiol ; 279(2): H601-9, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10924059

ABSTRACT

Severe ischemic injury or infarction of myocardium may cause activation of matrix metalloproteinases (MMPs) and damage the interstitial matrix. However, it is unknown whether MMP activation and matrix damage occur after moderate ischemia and reperfusion that result in myocardial stunning without infarction, and if so whether such changes contribute to postischemic myocardial expansion and contractile dysfunction. To address these questions, open-chest anesthetized pigs underwent 90 min of regional ischemia (subendocardial blood flow 0.4 +/- 0.1 ml. g(-1). min(-1)) and 90 min of reperfusion. After ischemia plus reperfusion, histological and ultrastructural examination revealed no myocardial infarction or inflammatory cell infiltration. Myocardial MMP-9 content increased threefold with a fourfold increase in the active form (P < 0.001). Myocardial collagenase content doubled (P < 0.01) but remained in latent form. MMP-2 and tissue inhibitors of metalloproteinases were unaffected. Despite increases in MMPs, collagen ultrastructure (assessed by cell maceration scanning electron microscopy) was unaltered. Intracoronary administration of the MMP inhibitor GM-2487 did not prevent or attenuate myocardial expansion (assessed by regional diastolic dimensions at near-zero left ventricular pressure) or contractile dysfunction. We conclude that although moderate ischemia and reperfusion alter myocardial MMP content and activity, these effects do not result in damage to interstitial collagen, nor do they contribute to myocardial expansion or contractile dysfunction.


Subject(s)
Collagen/ultrastructure , Hemodynamics , Matrix Metalloproteinases/metabolism , Myocardial Ischemia/pathology , Myocardial Ischemia/physiopathology , Myocardial Reperfusion , Myocardium/metabolism , Myocardium/ultrastructure , Animals , Blood Pressure , Collagenases/metabolism , Coronary Circulation , Female , Heart/physiopathology , Heart Rate , Matrix Metalloproteinase 9/metabolism , Myocardial Ischemia/metabolism , Myocardial Stunning/metabolism , Myocardial Stunning/pathology , Myocardial Stunning/physiopathology , Myocardium/pathology , Swine , Tissue Inhibitor of Metalloproteinases/metabolism , Ventricular Function, Left
17.
J Biol Chem ; 275(40): 31226-32, 2000 Oct 06.
Article in English | MEDLINE | ID: mdl-10900194

ABSTRACT

Of the four known tissue inhibitors of metalloproteinases (TIMPs), TIMP-3 is distinguished by its tighter binding to the extracellular matrix. The present results show that glycosaminoglycans such as heparin, heparan sulfate, chondroitin sulfates A, B, and C, and sulfated compounds such as suramin and pentosan efficiently extract TIMP-3 from the postpartum rat uterus. Enzymatic treatment by heparinase III or chondroitinase ABC also releases TIMP-3, but neither one alone gives complete release. Confocal microscopy shows colocalization of heparan sulfate and TIMP-3 in the endometrium subjacent to the lumen of the uterus. Immunostaining of TIMP-3 is lost upon digestion of tissue sections with heparinase III and chondroitinase ABC. The N-terminal domain of human TIMP-3 was expressed and found to bind to heparin with affinity similar to that of full-length mouse TIMP-3. The A and B beta-strands of the N-terminal domain of TIMP-3 contain two potential heparin-binding sequences rich in lysine and arginine; these strands should form a double track on the outer surface of TIMP-3. Synthetic peptides corresponding to segments of these two strands compete for heparin in the DNase II binding assay. TIMP-3 binding may be important for the cellular regulation of activity of the matrix metalloproteinases.


Subject(s)
Extracellular Matrix/metabolism , Glycosaminoglycans/metabolism , Sulfur/metabolism , Tissue Inhibitor of Metalloproteinase-3/metabolism , Alkylation , Animals , Chondroitin ABC Lyase/metabolism , Chondroitin Sulfates/metabolism , DNA, Complementary/metabolism , Dermatan Sulfate/metabolism , Dose-Response Relationship, Drug , Electrophoresis, Polyacrylamide Gel , Endometrium/metabolism , Escherichia coli/metabolism , Female , Gene Library , Heparin/metabolism , Heparitin Sulfate/metabolism , Humans , Kinetics , Mice , Microscopy, Confocal , Peptides/metabolism , Polysaccharide-Lyases/metabolism , Postpartum Period , Protein Folding , Protein Structure, Tertiary , Rats , Rats, Sprague-Dawley , Recombinant Proteins/metabolism , Suramin/metabolism , Tissue Inhibitor of Metalloproteinase-3/chemistry , Tissue Inhibitor of Metalloproteinase-3/genetics , Uterus/metabolism
18.
Am J Physiol Lung Cell Mol Physiol ; 279(1): L152-60, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10893214

ABSTRACT

The molecular mechanism(s) by which chemically complex air pollution particles mediate their adverse health effects is not known. We have examined the ability of combustion and ambient air particles to induce pulmonary matrilysin expression due to the well-documented role of matrix metalloproteinases in tissue injury and repair responses. Rats were exposed to saline, residual oil fly ash (2.5 mg/rat), or ambient air particles (2.5 mg/rat) via intratracheal instillation and examined 3-72 h after exposure. Saline-exposed animals had low levels of matrilysin mRNA, whereas the animals exposed to either complex particle showed an early induction of pulmonary matrilysin gene expression as well as of the 19-kDa activated form of matrilysin. Immunocytochemistry and in situ hybridization analyses identified the alveolar macrophages and monocytes as primary sources of air pollution particle-induced matrilysin expression. Matrilysin gene induction and protein activation by combustion and ambient air particles correlated with the early histopathological changes produced by these particles. These results demonstrate the ability of combustion and ambient air particles to induce pulmonary matrilysin expression and suggest a role for this matrix metalloproteinase in the initiation of lung injury produced by these particles.


Subject(s)
Air Pollutants/pharmacology , Carbon/pharmacology , Lung/metabolism , Matrix Metalloproteinase 7/metabolism , Animals , Coal Ash , Gene Expression/drug effects , Lung/drug effects , Lung/pathology , Male , Matrix Metalloproteinase 7/genetics , Particulate Matter , Rats , Rats, Sprague-Dawley , Sodium Chloride/pharmacology
19.
J Biol Chem ; 275(6): 4183-91, 2000 Feb 11.
Article in English | MEDLINE | ID: mdl-10660581

ABSTRACT

Many matrix metalloproteinases (MMPs) are tightly bound to tissues; matrilysin (MMP-7), although the smallest of the MMPs, is one of the most tightly bound. The most likely docking molecules for MMP-7 are heparan sulfate proteoglycans on or around epithelial cells and in the underlying basement membrane. This is established by extraction experiments and confocal microscopy. The enzyme is extracted from homogenates of postpartum rat uterus by heparin/heparan sulfate and by heparinase III treatment. The enzyme is colocalized with heparan sulfate in the apical region of uterine glandular epithelial cells and can be released by heparinase digestion. Heparan sulfate and MMP-7 are expressed at similar stages of the rat estrous cycle. The strength of heparin binding by recombinant rat proMMP-7 was examined by affinity chromatography, affinity coelectrophoresis, and homogeneous enzyme-based binding assay; the K(D) is 5-10 nM. Zymographic measurement of MMP-7 activity is greatly enhanced by heparin. Two putative heparin-binding peptides have been identified near the C- and N-terminal regions of proMMP-7; however, molecular modeling suggests a more extensive binding track or cradle crossing multiple peptide strands. Evidence is also found for the binding of MMP-2, -9, and -13. Binding of MMP-7 and other MMPs to heparan sulfate in the extracellular space could prevent loss of secreted enzyme, provide a reservoir of latent enzyme, and facilitate cellular sensing and regulation of enzyme levels. Binding to the cell surface could position the enzyme for directed proteolytic attack, for activation of or by other MMPs and for regulation of other cell surface proteins. Dislodging MMPs by treatment with compounds such as heparin might be beneficial in attenuating excessive tissue breakdown such as occurs in cancer metastasis, arthritis, and angiogenesis.


Subject(s)
Heparan Sulfate Proteoglycans/metabolism , Matrix Metalloproteinase 7/metabolism , Animals , Binding Sites , Chondroitinases and Chondroitin Lyases/metabolism , Computer Graphics , Endodeoxyribonucleases/antagonists & inhibitors , Enzyme Precursors/chemistry , Escherichia coli , Female , Fluorescent Antibody Technique , Heparin/metabolism , Heparitin Sulfate/metabolism , Humans , Metalloendopeptidases/chemistry , Peptide Fragments/immunology , Polysaccharide-Lyases/metabolism , Protein Binding , Rats , Rats, Sprague-Dawley , Recombinant Proteins , Uterus/metabolism
20.
Plant Physiol ; 121(3): 1003-15, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10557250

ABSTRACT

The addition of primary amines to the growth medium of the unicellular green alga Chlamydomonas reinhardtii disrupts cell wall assembly in both vegetative and zygotic cells. Primary amines are competitive inhibitors of the protein-cross-linking activity of transglutaminases. Two independent assays for transglutaminase confirmed a burst of extracellular activity during the early stages of cell wall formation in both vegetative cells and zygotes. When non-inhibiting levels of a radioactive primary amine ((14)C-putrescine) were added to the growth medium, both cell types were labeled in a reaction catalyzed by extracellular transglutaminase. The radioactive label was found specifically in the cell wall proteins of both cell types, and acid hydrolysis of the labeled material released unmodified (14)C-putrescine. Western blots of the proteins secreted at the times of maximal transglutaminase activity in both cell types revealed a single highly cross-reactive 72-kD band when screened with antibodies to guinea pig tissue transglutaminase. Furthermore, the proteins immunoprecipitated by this antiserum in vivo exhibited transglutaminase activity. We propose that this transglutaminase is responsible for an early cell wall protein cross-linking event that temporally precedes the oxidative cross-linking mediated by extracellular peroxidases.


Subject(s)
Chlamydomonas reinhardtii/physiology , GTP-Binding Proteins/metabolism , Membrane Proteins/metabolism , Transglutaminases/metabolism , Animals , Catalysis , Cell Wall/metabolism , Cross-Linking Reagents , Enzyme Inhibitors/pharmacology , GTP-Binding Proteins/chemistry , GTP-Binding Proteins/immunology , Kinetics , Protein Glutamine gamma Glutamyltransferase 2 , Putrescine/metabolism , Transglutaminases/chemistry , Transglutaminases/immunology , Zygote/physiology
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