Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Chain Migration”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,099 records · Page 61Linked to original sources
PubMed2003

Laminin-5 gamma 2 chain is colocalized with gelatinase-A (MMP-2) and collagenase-3 (MMP-13) in odontogenic keratocysts.

BACKGROUND: Odontogenic keratocyst (KC) differs from other epithelial odontogenic cysts in regard to increased epithelial proliferation and a strong tendency to recur. Laminin-5 (Ln-5) is an epithelial anchoring filament component, which after modulation by certain matrix metalloproteinases (MMPs), like MMP-2 and MMP-13, induces epithelial cell migration. METHODS: Using in situ hybridization and immunohistochemistry, we studied the Ln-5 gamma-2 chain expression related to the expression of MMP-2, -8, and -13 in different odontogenic cysts, including radicular cysts (RC; n = 11), follicular cysts (FC; n = 11), and odontogenic keratocysts (KC; n = 16). RESULTS: Ln-5 mRNA was present in all cysts examined, while less than half of KCs and RCs (33 and 40%, respectively) demonstrated MMP-2 mRNA. MMP-13 mRNA was present in all KC samples. Ln-5 protein was located as a continuous ribbon in BM zone of all KCs, and MMP-2 and MMP-13 immunoreactivities colocated significantly with Ln-5 in that area. MMP-8 was expressed by stromal macrophages and epithelial goblet cells, but never located in BM zone. CONCLUSIONS: Our results indicate that the colocalization of Ln-5 with MMP-2 or MMP-13, but not with MMP-8, in BM zone of KCs, may be related to special characteristics of KC.

Basement Membrane↗
PubMed1982

Epidermal cell migration on collagen and collagen-derived peptides.

Nucleopore filters coated with various genetic types of collagen and certain collagen-derived peptides were implanted under one margin of a skin wound on adult Notophthalmus viridescens (newt) hind limbs. In contrast to their behaviour on untreated filters, epidermal cells migrated readily and to equal degrees on human type I, newt type I, bovine type II, and bovine type IV collagen. Denaturation had no effect on the ability of collagen to support migration and all three cyanogen bromide peptides tested (alpha 1(I)CB3, 7 and 8) were able to support more migration than that seen on untreated filters. Glutaraldehyde-linked collagen gels supported migration but bovine serum albumin gels did not. These results show that there is no species or collagen-type specificity shown by newt epidermal cells as they migrate over collagen-coated substrates. They also demonstrate that the tertiary structure of the collagen molecule is unimportant in its ability to bind to newt epidermal cells, and that the alpha 1(I) chain has at least three, and probably many epidermal binding sites. Finally, they indicate that the improved migration on collagen is not a non-specific response to protein on the substrate.

Animals↗
PubMed2006

Profiling adipocytokine secretion from creeping fat in Crohn's disease.

BACKGROUND: Adipose tissue is recognized as a compartment secreting highly active molecules. Creeping fat represents a characteristic feature of Crohn's disease (CD). Proinflammatory or anti-inflammatory adipose-derived secretory products, now generally called adipocytokines, may play a role in the pathogenesis of CD. MATERIALS AND METHODS: Adipose tissue specimens were obtained from creeping fat contiguous to the involved intestine of 10 patients with CD. Mesenteric adipose tissue specimens resected from 13 patients with colon cancer (CC) and from 7 patients with diverticulitis served as controls. Three fat tissue specimen per well and 6 to 8 wells per patient were incubated ex vivo for 24 h. The release of adiponectin, resistin, leptin, interleukin-6, macrophage colony-stimulating factor, monocyte chemotactic protein-1, and migration inhibitory factor was measured by ELISA. The expression of AdipoR1 and AdipoR2 receptors was investigated by real-time quantitative polymerase chain reaction in a subset of adipose tissues. RESULTS: The secretion of adiponectin and macrophage colony-stimulating factor, as well as leptin and migration inhibitory factor, was significantly upregulated in CD compared with CC and diverticulitis or CC only, respectively. Resistin, interleukin-6, and monocyte chemotactic protein-1 were not specifically induced in CD but were associated with unspecific inflammation. Adiponectin receptor expression was not different in CC, CD, or diverticulitis. Steroid treatment in CD patients had differential effects on the ex vivo secretion of adipocytokines. CONCLUSIONS: A specific secretion pattern of proinflammatory and anti-inflammatory adipocytokines indicates the significance of adipose tissue in intestinal inflammation in CD. Future investigations of this intestinal compartment may provide novel insights into the pathophysiological role of creeping fat and CD.

Adipose Tissue↗
PubMed1992

Characterization of a recombinant chimeric plasminogen activator composed of a fibrin fragment-D-dimer-specific humanized monoclonal antibody and a truncated single-chain urokinase.

A recombinant chimeric plasminogen activator, MA-15C5Hu/scu-PA-32k, composed of a humanized fibrin fragment-D-dimer-specific monoclonal antibody (MA-15C5Hu) and a recombinant low-molecular-mass single-chain urokinase-type plasminogen activator, comprising amino acids Leu144-Leu411 (scu-PA-32k), was produced by cotransfecting Chinese hamster ovary (CHO) cells with the cDNA encoding the MA-15C5Hu light-chain sequence and the cDNA encoding the MA-15C5Hu heavy-chain sequence fused with the cDNA encoding scu-PA-32k. Purified MA-15C5Hu/scu-PA-32k migrated as a 215-kDa band on non-reducing SDS/PAGE, which is consistent with a molecule composed of one antibody and two scu-PA-32k moieties. However, the chimera was obtained as a mixture of single-chain u-PA-32k (37%) and amidolytically inactive (50%) and active (13%) two-chain u-PA-32k, the latter of which was removed by immunoadsorption on a monoclonal antibody specific for two-chain urokinase. The fragment-D-dimer affinity and enzymatic properties of MA-15CHu/scu-PA-32k were similar to those of MA-15C5Hu or of scu-PA-32k. In an in vitro system composed of a 125I-fibrin-labeled human plasma clot submerged in citrated human plasma, MA-15C5Hu/scu-PA-32k had a 12-fold higher fibrinolytic potency than scu-PA-32k: 50% lysis in 2 h required 0.43 +/- 0.12 micrograms u-PA-32k equivalent of the chimera/ml versus 5.4 +/- 0.3 micrograms/ml of scu-PA-32k (mean +/- SEM, n = 4). Addition of purified fibrin fragment-D dimer reduced the fibrinolytic potency of MA-15C5Hu/scu-PA-32k in a concentration-dependent way, indicating that the increased potency is the result of antibody targeting. Thus, a recombinant humanized antifibrin antibody/u-PA chimera has been obtained in which only the variable domains of the antibody moiety are of non-human origin. The chimera has intact antigen-binding capacity, u-PA enzymatic activity and a significantly increased fibrinolytic potency in a plasma medium in vitro.

Amino Acid Sequence↗
PubMed1991

The half-lives of platelet-derived growth factor A- and B-chain mRNAs are similar in endothelial cells and unaffected by heparin-binding growth factor-1 or cycloheximide.

Platelet-derived growth factor (PDGF) is mitogenic and chemotactic for vascular smooth muscle cells cultured in vitro, and, thus, may play a role in the smooth muscle cell proliferation and migration that occurs during atherosclerotic lesion development. Two related PDGF polypeptides, designated as the A and B chains, form functionally active PDGF-AA, AB, or BB dimers. The PDGF A- and B-chain genes are both transcribed in human umbilical vein endothelial (HUVE) cells and their expression is regulated by cytokines, growth factors, endotoxin, and phorbol ester. We reported previously that the angiogenic polypeptide heparin-binding growth factor (HBGF)-1 induces PDGF A-chain gene expression, but does not affect PDGF B-chain gene expression. In this study, we determined whether mRNA stabilization contributed to this induction by measuring the half-life of PDGF A-chain mRNA in quiescent, HBGF-1-stimulated, and proliferating HUVE cells. PDGF A-chain mRNA levels increase when quiescent HUVE cells are treated with the protein synthesis inhibitor cycloheximide; therefore, the effect of cycloheximide on PDGF A-chain mRNA decay was also investigated. The half-life of PDGF A-chain transcripts in quiescent cells was approximately 2.4 h and neither HBGF-1 nor cycloheximide significantly altered this decay rate. We also estimated the half-life of PDGF B-chain mRNA under the three different growth conditions and in the absence or presence of cycloheximide. The half-life in quiescent cells was approximately 1.8 h and was unaffected by HBGF-1 or protein synthesis inhibition. Therefore, the PDGF mRNAs have similar decay rates in HUVE cells, even though the 3' untranslated region of B-chain transcripts, but not A-chain transcripts, contains AU-rich sequence motifs postulated to confer rapid turnover in vivo.

Blotting, Northern↗
PubMed2004

Distinct roles for the alpha and beta subunits in the functions of integrin alphaMbeta2.

Integrin alphaMbeta2 (Mac-1, CD11b/CD18) is a noncovalently linked heterodimer of alphaM and beta2 subunits on the surface of leukocytes, where it plays a pivotal role in the adhesion and migration of these cells. Using HEK293 cells expressing alphaMbeta2 or the individual constituent chains on their surface, we analyzed the contributions of the alphaM or beta2 subunits to functional responses mediated by the integrin. In cells expressing only alphaM or beta2, the individual subunits were not associated with the endogenous integrins of the cells, and other partners for the subunits were not detected by surface labeling and immunoprecipitation under a variety of conditions. The alphaM cells mediated adhesion and spreading on a series of alphaMbeta2 ligands (fibrinogen, Factor X, iC3b, ICAM-1 (intercellular adhesion molecule-1), and denatured ovalbumin) but could not support cell migration to any of these. The spreading of the alphaM cells suggested an unanticipated linkage of this subunit to the cytoskeleton. The beta2 cells supported migration and attachment but not spreading on a subset of the alphaMbeta2 ligands. The heterodimeric receptor and its individual subunits were purified from the cells by affinity chromatography and recapitulated the ligand binding properties of the corresponding cell lines. These data indicate that each subunit of alphaMbeta2 contributes distinct properties to alphaMbeta2 and that, in most but not all cases, the response of the integrin is a composite of the functions of its individual subunits.

CD11b Antigen↗
PubMed2001

Myosin ii light chain phosphorylation regulates membrane localization and apoptotic signaling of tumor necrosis factor receptor-1.

Activation of myosin II by myosin light chain kinase (MLCK) produces the force for many cellular processes including muscle contraction, mitosis, migration, and other cellular shape changes. The results of this study show that inhibition or potentiation of myosin II activation via over-expression of a dominant negative or wild type MLCK can delay or accelerate tumor necrosis factor-alpha (TNF)-induced apoptotic cell death in cells. Changes in the activation of caspase-8 that parallel changes in regulatory light chain phosphorylation levels reveal that myosin II motor activities regulate TNF receptor-1 (TNFR-1) signaling at an early step in the TNF death signaling pathway. Treatment of cells with either ionomycin or endotoxin (lipopolysaccharide) leads to activation of myosin II and increased translocation of TNFR-1 to the plasma membrane independent of TNF signaling. The results of these studies establish a new role for myosin II motor activity in regulating TNFR-1-mediated apoptosis through the translocation of TNFR-1 to or within the plasma membrane.

Animals↗
PubMed2006

Cytokine pattern determines the progression of experimental periodontal disease induced by Actinobacillus actinomycetemcomitans through the modulation of MMPs, RANKL, and their physiological inhibitors.

OBJECTIVE: Inflammatory and immune reactions raised in response to periodontopathogens are thought to trigger periodontal tissue destruction. We therefore investigated the expression of matrix metalloproteinases (MMPs) and the osteoclastogenic factor RANKL (receptor activator of nuclear factor-kappaB ligand), their respective inhibitors TIMPs (tissue inhibitors of metalloproteinases) and OPG (osteoprotegerin) and their possible correlation with the expression of inflammatory and regulatory cytokines in the course of experimental periodontal disease in mice. METHODS: We characterized the time course of leukocyte migration and alveolar bone loss in C57BL/6 mice infected with Actinobacillus actinomycetemcomitans. Quantitative polymerase chain reaction (RealTime PCR) and ELISA were performed to determine the expression of MMPs, TIMPs, RANKL, OPG and cathepsin K, interleukin-1beta, tumor necrosis factor-alpha, interferon-gamma, interleukin-12, interleukin-4 and interleukin-10 in periodontal tissue samples harvested throughout the course of experimental disease. RESULTS: Oral inoculation of A. actinomycetemcomitans results in an intense and widespread migration of leukocytes to the gingival tissues, besides marked alveolar bone resorption. Our data also demonstrate two distinct patterns of MMP/TIMP and RANKL/OPG expression in the course of experimental periodontal disease. The expression of MMPs (MMP-1, 2 and 9) and RANKL was correlated with the expression of interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma, in a time period characterized by the intense increase of inflammatory reaction and alveolar bone loss. On the other hand, interleukin-4 and interleukin-10 were associated with higher expression of TIMPs (TIMP 1, 2 and 3) and OPG, with a lower expression of MMPs and RANKL, and with reduced rates of increase of cellular infiltration in periodontal tissues and alveolar bone loss. CONCLUSIONS: It is possible that the pattern of cytokines produced in periodontal tissues determines the progression and the severity of experimental periodontal disease, controlling the breakdown of soft and bone tissues through the balance between MMPs/TIMP and RANKL/OPG expression in gingival tissues.

Actinobacillus Infections↗
PubMed2003

Structural dynamics of myoglobin: ligand migration and binding in valine 68 mutants.

We have combined Fourier transform infrared/temperature derivative (FTIR-TDS) spectroscopy at cryogenic temperatures and flash photolysis at ambient temperature to examine the effects of polar and bulky amino acid replacements of the highly conserved distal valine 68 in sperm whale myoglobin. In FTIR-TDS experiments, the CO ligand can serve as an internal voltmeter that monitors the local electrostatic field not only at the active site but also at intermediate ligand docking sites. Mutations of residue 68 alter size, shape, and electric field of the distal pocket, especially in the vicinity of the primary docking site (state B). As a consequence, the infrared bands associated with the ligand at site B are shifted. The effect is most pronounced in mutants with large aromatic side chains. Polar side chains (threonine or serine) have only little effect on the peak frequencies. Ligands that migrate toward more remote sites C and D give rise to IR bands with altered frequencies. TDS experiments separate the photoproducts according to their recombination temperatures. The rates and extent of ligand migration among internal cavities at cryogenic temperatures can be used to interpret geminate and bimolecular O2 and CO recombination at room temperature. The kinetics of geminate recombination can be explained by steric arguments alone, whereas both the polarity and size of the position 68 side chain play major roles in regulating bimolecular ligand binding from the solvent.

Amino Acid Substitution↗
PubMed1995

Association of p53 gene and protein alterations with metastases in colorectal cancer.

Using monoclonal antibody PAb 1801, p53 protein was detected in the neoplastic cells of 39 (46.9%) of 83 colorectal carcinomas studied. Patients with p53+ tumors showed a higher incidence of lymph node and liver metastases (p = 0.035); in patients whose tumors were located in the rectosigmoid, p53 expression also correlated with a more advanced stage according to Dukes' classification (p = 0.015) as well as nodal (p = 0.006) and liver (p = 0.019) metastases. Following amplification of exons 5 to 8 of the p53 gene by means of the polymerase chain reaction technique, single-strand conformation polymorphism analysis disclosed an anomalous migration pattern in 23 of the 39 p53+ tumors and in four of the 35 p53- tumors analyzed. Sequence analysis showed G:C-->A:T transitions in 63.6%, G:C-->T:A and G:C-->C:G transversions in 18.2%, deletions and insertions in 13.6%, and A:T-->G:C transitions in 4.6% of the cases. Loss of heterozygosity was studied in the DNA of 79 patients; allelic loss was found in 29 (49.1%) of the 59 informative patients. Loss of heterozygosity was correlated with p53 overexpression (p = 0.0002) as well as with the presence of mutations as detected by single strand conformation polymorphism analysis (p = 0.0024).

Adenocarcinoma↗
PubMed2001

Expression of macrophage migration inhibitory factor during Pseudomonas keratitis.

Macrophage migration Inhibitory factor (MIF) is a recently rediscovered pro-inflammatory cytokine, and has been shown to play a role in the regulation of neutrophil chemokines and angiogenesis. Corneal epithelial and endothelial cells have been shown to express MIF. This study evaluated the expression of MIF during Pseudomonas keratitis in mice and in vitro using a corneal epithelial cell line. Three strains of P. aeruginosa, 6294 (invasive strain), 6206 (cytotoxic strain) and Paer1 (non-infectious strain) were used. Both cytotoxic and invasive strains were isolated from human corneal ulcers and the Paer1 strain was isolated from a non-infectious condition. Following challenge in mouse corneas or a corneal epithelial cell line, corneal homogenates or lysed corneal epithelial cells were used to isolate RNA. Migration inhibitory factor mRNA expression in the mouse cornea or human corneal epithelial cells was examined by reverse transcription-polymerase chain reaction analysis, and was found to be expressed as early as 4 h after the injury (scratch controls) or infection in the mouse corneas. Migration inhibitory factor mRNA in scratch controls and Paer1-inoculated corneas showed peak levels at 4 h post-challenge and this dropped by 24 h post-challenge. Corneas challenged with invasive and cytotoxic strains showed peak expression 24 h post-challenge. Migration inhibitory factor mRNA levels were significantly higher in invasive and cytotoxic strain inoculated corneas compared to Paer1 inoculated corneas. Challenging the corneal epithelial cell line with Pseudomonas 6294 and 6206 strains induced peak expression at 8 h and levels were decreased by 12 h. Epithelial cells inoculated with recombinant human interleukin-1beta protein induced very high levels of MIF mRNA at all time points compared to infected and control corneal epithelial cells. High expression of MIF in the infected corneas suggests that it may have a role in the pathogenesis of corneal disease induced by invasive and cytotoxic strains of P. aeruginosa.

Animals↗
PubMed1992

Isoprenoid modification of proteins distinct from membrane acyl proteins in the prokaryote Acholeplasma laidlawii.

Isoprenylation is an important posttranslational modification that affects the activity, subunit interactions and membrane anchoring of different eukaryotic proteins. The small, cell-wall-less prokaryote Acholeplasma laidlawii has more than 20 membrane acyl-proteins enriched in myristoyl and palmitoyl chains. Radioactive mevalonate, a precursor to isoprenoids, was incorporated into several specific membrane proteins of 20 to 45 kDa and two soluble proteins of 23-25 kDa, respectively. No acyl proteins and none of the polar acyl lipids became labelled but these are all labelled by radioactive fatty acids. Mevalonate was incorporated mainly into a minor neutral, non-saponifiable lipid which migrated just above a C30-isoprenoid (squalene) on TLC-plates. The isoprenoid chains could not be released by mild alkaline hydrolysis from most of the isoprenylated proteins, although this procedure releases acyl chains from lipids and all acylated proteins. Isoprenylated proteins were enriched in the detergent phase upon partition with the non-ionic detergent Triton X-114. This behaviour is similar to the acyl proteins of this organism and indicates that the isoprenoid chains give the proteins a hydrophobic character.

Acholeplasma laidlawii↗
PubMed1982

Murine I-Ak alpha-chain subspecies with glycosylation differences.

In isolating homogeneous populations of murine Ia antigens by SDS-PAGE we have found that immunoprecipitated I-Ak molecules from whole spleen possess an electrophoretically heterogeneous population of alpha-chains. SDS-PAGE of 3H-mannose-labeled I-Ak immunoprecipitates revealed that the alpha-chain peak was divided into three regions (alpha 1, alpha 2, and alpha 3), each of which migrated as a distinct individual band when isolated and reelectrophoresed. Only alpha 1 and alpha 2 labeled with 3H-fucose. Nonequilibrium pH gradient electrophoresis excluded the possibility that any of the species was invariant chain, but rather suggested that the subspecies were structurally related and that alpha 3 has fewer sialic acid residues than alpha 1 and alpha 2. Sialic acid differences between alpha 1, alpha 2, and alpha 3 were further suggested by SDS-PAGE and by peptide mapping of neuraminidase-treated immunoprecipitates. Tryptic peptide maps of 3H-leucine-labeled alpha 1, alpha 2, and alpha 3 were identical, indicating that the polypeptide backbone of the molecules is the same for all subspecies. Our results suggest that alpha 1 and alpha 2 have fucose and sialic acid and thus possess complex type oligosaccharides, whereas alpha 3 lacks these sugars and possess high mannose-type saccharides. The potential relationships of the alpha-chain subspecies is discussed. In addition, we demonstrate the usefulness of high-pressure liquid chromatography in the isolation of glycopeptides for their subsequent analysis.U

Animals↗
PubMed1988

Drosophila substrate adhesion molecule: sequence of laminin B1 chain reveals domains of homology with mouse.

Laminin, a substrate adhesion molecule in vertebrates, is a large glycoprotein complex in basement membranes that promotes cell adhesion, cell migration, and neurite outgrowth. Here we report on the cloning of the genes encoding the three subunits of Drosophila laminin. Sequence analysis of cDNA clones encoding the Drosophila B1 chain reveals a multidomain structure similar to that of its mouse homolog. The Drosophila sequence has only 25% amino acid identity with the mouse sequence in domains I, II, and IV. However, in one of the putative collagen-binding regions (domain VI) and the two cysteine-rich domains of EGF-like repeats (domains III and V), the amino acid identity between these two evolutionarily distant species jumps to 55%. Moreover, the number, length, and unique amino acid sequences of each of the 13 EGF-like repeats are highly conserved between Drosophila and mouse, suggesting that each may serve a unique function in protein-protein interactions.

Amino Acid Sequence↗
PubMed2001

Migration behavior of alkylphenols, bisphenol A and bisphenol S studied by capillary electrophoresis using sulfated beta-cyclodextrin.

An application of capillary electrophoresis (CE) using sulfated beta-cyclodextrin (SCD) has been investigated for separating alkylphenols with different chain lengths, as well as bisphenol A and bisphenol S. In the absence of SCD in running buffer, all the phenols migrated at the same velocity as the electroosmotic flow (EOF), whereas the addition of SCD effectively led to the baseline separation of alkylphenols on the basis of the difference in the abilities to bind into the hydrophobic cavity of CD. The host-guest binding constants between analyte phenols and SCD were evaluated from Benesi-Hildebrand plots of the data obtained by two independent methods, CE and UV-visible measurements, demonstrating that the greater the hydrophobicity of the phenols, the larger the binding constants. The effects of organic solvents on the resolution for alkylphenols and bisphenols were also examined. This system using SCD was effective for the separation of 4-octylphenol and 4-nonylphenol isomers having longer alkyl chains.

Journal Article↗
PubMed1997

Soluble low density lipoprotein receptor-related protein (LRP) circulates in human plasma.

Our studies have identified a soluble molecule in normal human plasma and serum with the characteristics of the alpha-chain of the low density lipoprotein receptor-related protein (LRP). LRP is a large multifunctional receptor mediating the clearance of diverse ligands, including selected lipoproteins, various protease inhibitor complexes, and thrombospondin. A soluble molecule (sLRP) has been isolated from plasma using an affinity matrix coupled with methylamine-activated alpha2-macroglobulin, the ligand uniquely recognized by LRP, and eluted with EDTA. This eluate contains a protein that co-migrates on SDS-polyacrylamide gel electrophoresis with authentic human placental LRP alpha-chain, is recognized by anti-LRP alpha-chain monoclonal antibodies, and binds the 39-kDa receptor-associated protein (RAP) and tissue plasminogen activator-inhibitor complexes. A similar RAP-binding molecule was detected in medium conditioned for 24 h by primary cultures of rat hepatocytes, suggesting that the liver may be the in vivo source of sLRP. In contrast, immunoprecipitation experiments failed to detect the production of sLRP by cultured HepG2 hepatoma and primary human fibroblast cells. Addition of a soluble form of LRP to cultured HepG2 cells resulted in a significant inhibition of capacity of these cells to degrade tPA, a process that has been demonstrated to be mediated by cell surface LRP. Preliminary data indicate that the concentration of sLRP is altered in the plasma of patients with liver disease. Increased levels of sLRP may antagonize the clearance of ligands by cell bound LRP perturbing diverse processes including lipid metabolism, cell migration and extracellular proteinase activity.

Animals↗
PubMed1990

Definition of a sequence, RYVVLPR, within laminin peptide F-9 that mediates metastatic fibrosarcoma cell adhesion and spreading.

A synthetic peptide from the inner globule of the B1 chain of laminin, termed peptide F-9 (RYVVLPRPVCFEKGMNYTVR; residues 641-660), has been shown to have heparin-binding and cell adhesion-promoting activities for diverse cell types (Charonis et al., J. Cell. Biol., 107: 1253-1260, 1988). In this study, the metastatic murine fibrosarcoma cell line, UV-2237-MM, adhered and spread on surfaces coated with laminin and peptide F-9 in a concentration- and time-dependent fashion. Cells migrated toward laminin in Boyden microchemotaxis chambers but not toward peptide F-9. However, exogenous soluble peptide F-9 inhibited both the adhesion and migration of cells toward laminin. Polyclonal antibodies raised against peptide F-9 were capable of inhibiting laminin-mediated cell adhesion and migration. Peptide F-9 is located 265 residues from CDPGYIGSR, another sequence on the B1 chain of laminin which has been reported by others to promote cell adhesion (Graft et al., Cell, 48: 989-996, 1987). In contrast to peptide F-9, various control peptides including CDPGYIGSR did not promote the adhesion, spreading, or migration of the UV-2237-MM fibrosarcoma cells. In addition, neither exogenous peptide CDPGYIGSR nor antibodies raised against peptide CDPGYIGSR were capable of inhibiting laminin-mediated cell adhesion or migration. These results indicate that peptide F-9, but not peptide CDPGYIGSR, represents a major fibrosarcoma cell adhesion-promoting domain on intact laminin. A series of overlapping peptides were synthesized which contained various portions of the parent peptide F-9. The use of these peptides in cell adhesion assays demonstrated that the sequence RYVVLPR from the amino terminus of peptide F-9 was essential for cell adhesion-promoting activity.

Amino Acid Sequence↗
PubMed2002

Activation of p38 MAP-kinase and caldesmon phosphorylation are essential for urokinase-induced human smooth muscle cell migration.

We have explored intracellular pathways involved in the urokinase type plasminogen activator (urokinase or uPA)-stimulated migration of human airway smooth muscle cells (hAWSMC). Using a set of uPA mutants we found that protease activity, growth factor-like and kringle domains of uPA differentially contribute to activation of p42/p44erk1,2 and p38 MAP-kinases. Consistent with our earlier data [Mukhina et al., J. Biol. Chem. 275 (2000), 16450-16458], the kringle domain of uPA was sufficient and required to stimulate cell motility. Here we report that uPA mutants containing the kringle domain specifically activate the p38 MAP-kinase pathway and actomyosin by increasing phosphorylation of the critical Ser-19 on the myosin regulatory light chain and MAP-kinase sites of the actin-associated regulatory protein caldesmon. While pharmacological inhibition of p38 MAP-kinase activation did not affect myosin light chain phosphorylation, it blocked the increase in caldesmon phosphorylation and uPA-stimulated migration of hAWSMC on a collagen-coated surface. We conclude that activation of p38 MAP-kinase and downstream phosphorylation of non-muscle caldesmon is essential for urokinase-stimulated smooth muscle cell migration.

Calmodulin-Binding Proteins↗