Search results for "carrier protein"
showing 10 items of 361 documents
Biosynthesis of Lipopolysaccharide-Binding Protein in Rabbit Hepatocytes
1990
Studies reported here show that the recently discovered acute-phase protein, lipopolysaccharide-binding protein (LBP), is synthesized by hepatocytes. For these studies, explanted rabbit hepatocytes were grown in the presence of 35S-methionine. Biosynthetically labelled LBP in the cells and supernatant was identified using immunoprecipitation with rat anti-rabbit LBP antibody. This antibody immunoprecipitates both the LBP polypeptide and the glycosylated protein. With a cell-free translation system a comparison of RNA from normal rabbit liver with that isolated from acute-phase rabbit liver indicated that a translatable LBP message is only found in the RNA from acute-phase liver. Studies wit…
Protein Kinase C μ Is Regulated by the Multifunctional Chaperon Protein p32
2000
We identified the multifunctional chaperon protein p32 as a protein kinase C (PKC)-binding protein interacting with PKCalpha, PKCzeta, PKCdelta, and PKC mu. We have analyzed the interaction of PKC mu with p32 in detail, and we show here in vivo association of PKC mu, as revealed from yeast two-hybrid analysis, precipitation assays using glutathione S-transferase fusion proteins, and reciprocal coimmunoprecipitation. In SKW 6.4 cells, PKC mu is constitutively associated with p32 at mitochondrial membranes, evident from colocalization with cytochrome c. p32 interacts with PKC mu in a compartment-specific manner, as it can be coimmunoprecipitated mainly from the particulate and not from the so…
Dissection of human papillomavirus type 33 L2 domains involved in nuclear domains (ND) 10 homing and reorganization
2003
Abstract We have recently shown that the minor capsid protein L2 of human papillomavirus type 33 (HPV33) recruits the transcriptional repressor Daxx into nuclear domains (ND) 10 and causes the loss of the transcriptional activator Sp100 from these subnuclear structures (Florin et al., 2002b) . In order to dissect L2 domains involved in nuclear translocation, ND10 homing, loss of Sp100, and recruitment of Daxx, a detailed deletion mutagenesis of L2 was performed. Using immunofluorescence and green fluorescent protein fusions, we have identified two nuclear localization signals (NLS) in the central and C-terminal part of L2, respectively, homologous to previously identified NLS in HPV6B L2 (S…
Na+ dependent glutamate transporters (EAAT1, EAAT2, and EAAT3) in primary astrocyte cultures: effect of oxidative stress.
2001
Abstract The Na + -dependent l -glutamate transporters EAAT1(GLAST), EAAT2 (GLT-1) and EAAT3 (EAAC1) are expressed in primary astrocyte cultures, showing that the EAAT3 transporter is not neuron-specific. The presence of these three transporters was evaluated by RT–PCR, immunoblotting, immunocytochemical techniques, and transport activity. When primary astrocyte cultures were incubated with l -buthionine-( S , R )-sulfoximine (BSO), a selective inhibitor of γ-glutamylcysteine synthetase, the GSH concentration was significantly lower than in control cultures, but the expression and amount of protein of EAAT1, EAAT2 and EAAT3 and transport of l -glutamate was unchanged. Oxidative stress was c…
Utilization of hemin and hemoglobin by Vibrio vulnificus biotype 2
1996
The eel pathogen Vibrio vulnificus biotype 2 is able to use hemoglobin (Hb) and hemin (Hm) to reverse iron limitation. In this stud, the adjuvant effect of both compounds on eel pathogenicity has been evaluated and confirmed. Further, we have studied the heme-iron acquisition mechanism displayed by this bacterium. Whole cells were capable of binding Hb and Hm, independently of (i) iron levels in growth medium and (ii) the presence of polysaccharide capsules on bacterial surface. The Hb- and Hm-binding capacity was retained by the outer membrane protein (OMP) fraction and was abolished after proteolytic digestion of OMP samples. Western blotting (immunoblotting) of denatured OMPs revealed th…
The cell adhesion domain of type XVII collagen promotes integrin-mediated cell spreading by a novel mechanism.
2001
Type XVII collagen (BP180) is a keratinocyte transmembrane protein that exists as the full-length protein in hemidesmosomes and as a 120-kDa shed ectodomain in the extracellular matrix. The largest collagenous domain of type XVII collagen, COL15, has been described previously as a cell adhesion domain (Tasanen, K., Eble, J. A., Aumailley, M., Schumann, H., Baetge, J, Tu, H., Bruckner, P., and Bruckner-Tuderman, L. (2000) J. Biol. Chem. 275, 3093-3099). In the present work, the integrin binding of triple helical, human recombinant COL15 was tested. Solid phase binding assays using recombinant integrin alpha(1)I, alpha(2)I, and alpha(10)I domains and cell spreading assays with alpha(1)beta(1)…
Human kininogens interact with M protein, a bacterial surface protein and virulence determinant.
1995
Streptococcus pyogenes, the most significant streptococcal species in clinical medicine, expresses surface proteins with affinity for several human plasma proteins. Here we report that kininogens, the precursors to the vasoactive kinins, bind to the surface of S. pyogenes. M protein, a surface molecule and a major virulence factor-in these bacteria, occurs in > 80 different serotypes. Among 49 strains of S. pyogenes, all of different M serotypes, 41 bound radiolabelled kininogens, whereas 6 M protein-negative mutant strains showed no affinity. M protein of most serotypes bind fibrinogen, and among the 55 strains tested, binding of kininogens was closely correlated to fibrinogen bindi…
Kininogen binding protein p33/gC1qR is localized in the vesicular fraction of endothelial cells
1996
AbstractThe endothelial protein p33/gC1qR is thought to mediate the assembly of components of the kinin-forming and complement-activating pathways on the surface of cardiovascular cells. FACS analysis of intact human umbilical vein endothelial cells using specific antibodies to p33 revealed a minor fluorescence on the cell surface whereas permeabilized cells showed a bright fluorescence indicative of an intracellular localization of p33. Immunostaining of fixed cells confirmed the predominant intracellular localization of p33. Fractionation studies demonstrated that the vesicular but not the membrane fraction of EA.hy926 cells is rich in p33. We conclude that externalization of p33 must pre…
Paracrine dialogue in implantation
2002
We know that the implantation process requires a functionally normal embryo at the blastocyst stage and a receptive endometrium, but also a communication link between them is needed. This paracrine dialogue between the embryo, endometrium and the corpus luteum are known to occur in ruminants and primates, more specifically endometrial-embryonic interactions have been reported in rodents and primates but not in humans. This process is a highly regulated mechanism and many molecules take part in this cross-talk. Here, we present updated information in humans on the embryonic regulation of endometrial epithelial molecules such as chemokines, adhesion and anti-adhesion molecules, and leptin dur…
Insertion of light-harvesting chlorophyll a/b protein into the thylakoid
2000
The major light-harvesting chlorophyll a/b-binding protein (Lhcb1,2) of photosystem II is inserted into the thylakoid via the signal recognition particle dependent pathway. However, the mechanism by which the protein enters the membrane is at this time unknown. In order to define some topographical restrictions for this process, we constructed several recombinant derivatives of Lhcb1 carrying hexahistidine tags at either protein terminus or in the stromal loop domain. Additionally, green fluorescent protein (GFP) was fused to either terminus. None of the modifications significantly impair the pigment-binding properties of the protein in the in vitro reconstitution of LHCII. With the excepti…