| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.78388059 |
| Indeed , the kinetics or the extent of cleavage of C4b are not affected by greatly augmenting the concentration of exogenous CR 1 or of C4b bearing red cells in the incubation mixture , thereby increasing the frequency of collisions between CR 1 on the surface of one cell with C4b deposited on the membrane of a different cell . 0.78388059^^^ We show that deposited C4b interacts endogenously with complement receptor type 1 ( CR 1 ) present on the membrane of the same red cell . 0.51633774^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.618876 |
| It has been claimed that patients with systemic lupus erythematosus ( SLE ) have an inherited deficiency of erythrocyte complement receptor type 1 ( CR 1 , with ligand binding specificity for C3b , iC3b and C4b ) . 0.618876^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Differences between C4A and C4B in the handling of immune complexes : the enhancement of CR 1 binding is more important than the inhibition of immunoprecipitation . ^^^ In this study we have compared purified C4A and C4B with regard to their ability to prevent immune complex precipitation and to enhance the binding of both preformed and nascent immune complexes to the receptor CR 1 on red cells . ^^^ In the CR 1 binding assay C4A was markedly more effective than C4B in enhancing binding to CR 1 . ^^^ Thus the major differences between C4A and C4B in regard to immune complex handling is at the level of CR 1 binding . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The two classes of human complement component C 4 proteins C4A and C4B manifest differential chemical reactivities and binding affinities towards target surfaces and complement receptor CR 1 . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Several previous reports concluded that the C4b fragment of human C4A ( C4Ab ) binds with higher affinity to CR 1 than does C4Bb . ^^^ Because the isotypic residues , ( 1101 ) PCPVLD and ( 1101 ) LSPVIH in C4A and C4B , respectively , are located within the C4d region , one may have expected a direct binding contribution of C4d to the interaction with CR 1 . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| E capture IC via complement receptors , type 1 ( CR 1 ) which can bind to C3b and C4b ligand sites generated on IC during activation of the complement cascade . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Factor 1 dependent inactivation of human complement C4b of the classical pathway by C3b / C4b receptor ( CR 1 , CD 35 ) and membrane cofactor protein ( MCP , CD 46 ) . ^^^ A plasma protease factor 1 and membrane cofactors , C3b / C4b receptor ( CR 1 ) and membrane cofactor protein ( MCP ) , participate in the regulation of cell bound C4b although the physiological potency of these cofactors remains unknown . ^^^ CR 1 being a cofactor at a cofactor / C4b ratio less than 0 . 1 ( w / w ) , fluid phase C4b , and methylamine treated C 4 ( C4ma ) were degraded by factor 1 into C4bi : minimal Cd 4 was generated in the fluid phase . ^^^ CR 1 showed two optimal pHs ( 6 . 0 and 7 . 5 ) for fluid phase C4b , but one ( 6 . 0 ) for LAC4b , and in both cases low conductivity conditions enhanced the C4bi generation . ^^^ Furthermore , as in the case of C3b cleavage , a sufficient NP 40 concentration to solubilize membrane was needed for MCP to express full cofactor activity for C4b , in contrast to CR 1 . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| These genes give rise to the isotypic forms C4A and C4B , and recent studies suggest that CR 1 binds activated C4A ( C4Ab ) to a greater extent than activated C4B ( C4Bb ) . ^^^ The binding reaction between immune complexes with equivalent amounts of covalently bound C4Ab or C4Bb and erythrocyte CR 1 showed a two fold higher binding of complexes coated with C4A . ^^^ Furthermore , erythrocyte CR 1 bound C4Ab2 with an apparent four fold higher affinity ( Kd approximately 1 . 4 10 10 ( 7 ) M ) than C4Bb2 ( Kd approximately 4 . 8 10 10 ( 7 ) M ) , indicating a preferential binding of CR 1 for C4A . . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Cell surface expression of the C3b / C4b receptor ( CR 1 ) protects Chinese hamster ovary cells from lysis by human complement . ^^^ The C3b / C4b receptor , also known as complement receptor type 1 ( CR 1 , CD 35 ) , is a single chain glycoprotein consisting of 30 repeating homologous protein domains known as short consensus repeats ( SCR ) followed by transmembrane and cytoplasmic domains . ^^^ The SCR 1 4 of CR 1 , but not SCR 1 2 , also inhibited complement lysis of the host CHO cell , indicating that more than two SCR are necessary and that four SCR are sufficient for optimal C4b binding to CR 1 . ^^^ Thus , the structural requirements for C4b binding are analogous to those for C3b binding , namely , four SCR of CR 1 form the binding sites for each of these proteins . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Human CR 1 is composed of tandem long homologous repeating ( LHR ) segments that encode separate binding sites for C3b or C4b . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Sites within the complement C3b / C4b receptor important for the specificity of ligand binding . ^^^ The latter , composed of the first eight and one half amino terminal SCRs of CR 1 , efficiently bound C4b but not iC 3 . ^^^ Analysis of the mutant CR 1 4 proteins , in which amino acids in SCR 1 and SCR 2 were substituted a few at a time with the homologous amino acids of SCR 8 and SCR 9 , led to the identification of one amino acid in SCR 1 and three amino acids in SCR 2 important for C4b binding . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Zinc ions inhibit factor 1 mediated release of CR 1 bound immune complexes and degradation of cell bound complement factors C3b and C4b . ^^^ We conclude that ZnCl 2 inhibited factor 1 activity since : ( 1 ) release of complement preopsonized IC from E CR 1 by purified factor 1 was markedly inhibited ( 90 % ) in the presence of ZnCl 2 , ( 2 ) preincubation of the cells with ZnCl 2 caused only a moderate inhibition ( 32 38 % ) of the IC release , and ( 3 ) degradation by purified factor 1 of covalently cell bound C3b and C4b was abrogated in the presence of 10 mM ZnCl2 . . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Binding studies using purified decay accelerating factor ( DAF ) , CR 1 , and Factor H indicate that the primary interaction of DAF with C 3 convertases is with the Bb or C2a subunits , whereas CR 1 and Factor H interact primarily with the C3b or C4b subunits . ^^^ The ability of soluble DAF , CR 1 , or Factor H to decay C3b , Bb bound to zymosan was inhibited by various concentrations of fluid phase competitors ( C3b , Bb , C3b , Bb , C3b , B , C4b , or C4b , C2a ) in 0 . 1 % NP 40 at 22 degrees C . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| E from primates demonstrate type 1 CR ( CR 1 ) with binding specificities for C3b and C4b . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Similar repetitive units are present in the C4b binding protein , the C3b receptor ( CR 1 ) , complement factor B and C 2 , and in beta 2 glycoprotein 1 and the interleukin 2 receptor . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Human C3b / C4b receptor ( CR 1 ) . ^^^ The linear alignment of 30 SCRs as a semi rigid structure would extend 1 , 140A from the plasma membrane and might facilitate the interaction of CR 1 with C3b and C4b located within the interstices of immune complexes and microbial cell walls . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The determination of primary structures by amino acid and nucleotide sequencing for the C3b and / or C4b binding proteins H , C4BP , CR 1 , B , and C 2 has revealed the presence of a common structural element . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| E ( erythrocyte ) bearing C3b or C4b adhered to sections of myelinated peripheral nerves and the binding was inhibited only by anti CR 1 antibodies . ^^^ E bearing C3b or C4b did not adhere to unmyelinated nerves from adults or to nerves from fetuses at a gestational age of approximately 21 weeks , whereas monoclonal anti CR 1 antibodies stained myelinated , unmyelinated and fetal nerves equally well . ^^^ The results indicate that CR 1 in unmyelinated and fetal nerves are either functionally inactive or express a lower affinity for C3b / C4b than CR 1 in myelinated nerves . ^^^ There were no significant differences in the binding of E bearing C3b or C4b to myelinated peripheral nerves from 50 individuals , indicating that CR 1 activity is not distributed phenotypically . . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Identification of distinct C3b and C4b recognition sites in the human C3b / C4b receptor ( CR 1 , CD 35 ) by deletion mutagenesis . ^^^ COS cells transfected with piABCD transiently expressed recombinant CR 1 that comigrated with the F allotype of erythrocyte CR 1 on SDS PAGE and that mediated rosette formation with sheep erythrocytes bearing C4b and C3b . ^^^ The presence of these three distinct sites in CR 1 may enable the receptor to interact multivalently with C4b / C3b and C3b / C3b complexes generated during activation of the classical and alternative pathways . . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Addition of antibodies against CR 1 and CR 2 or proteolytic removal of these complement receptors with trypsin inhibited by about 60 % the enhancing effect of TT bound C3b and C4b in both binding and functional assays . ^^^ These results indicate that binding of C3b or C4b to antigen enhances antigen specific proliferative and cytotoxic responses of T cells by targeting opsonized antigen onto complement receptors CR 1 and CR 2 of LCL . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| We examined the effects of C1q on C3b / C4b receptor ( CR 1 ) mediated phagocytosis by mononuclear phagocytes . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| These molecules are factor H , CR 1 ( C3b / C4b receptor ) , CR 2 ( C3d / EBV receptor ) , C4BP ( C4b binding protein ) , DAF ( decay accelerating factor ) , MCP ( membrane cofactor protein ; earlier designated p45 / 70 ) , CR 3 ( iC3b receptor or Mac 1 ) and CR 4 ( protein 150 / 95 ) . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Amino acid sequence analysis of tryptic peptides of CR 2 revealed a strong degree of homology with the human C3b / C4b receptor , CR 1 . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Based on preliminary evidence indicating that a cell associated protein of U 937 ( a human monocyte like cell line ) possessed cofactor activity and was not the C3b / C4b receptor , we sought to further characterize this protein . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The complement receptor for C3b of the epithelial cells of human glomeruli is structurally and functionally very similar or identical to CR 1 , the complement receptor for C3b and C4b present on the membrane of red cells and leukocytes . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Control of the function of substrate bound C4b C3b by the complement receptor Cr 1 . ^^^ The complement fragments C3b and C4b are the main ligands for the membrane receptor CR 1 . ^^^ One of the main findings of the present paper is that CR 1 also promotes the degradation of bound C4b ( * C4b ) into C4c and * C4d . ^^^ On a weight basis , the cofactor activity of CR 1 in the cleavage of * C4b present on the cell intermediate EAC 14 is 10 ( 3 ) fold greater than that of the serum cofactor C 4 binding protein ( C4bp ) . ^^^ An additional finding is that the effect of CR 1 on either * C3b or * C4b is modulated by the presence of the other ligand in its vicinity ; that is , * C4b degradation by CR 1 plus 1 is enhanced by neighboring * C3b and vice versa . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Moreover , the inhibitory activity of intact human erythrocytes on C4b2a was not blocked by antibodies to DAF , but was abolished by antibodies to the C3b / C4b receptor ( CR 1 ) . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Purification and functional analysis of the polymorphic variants of the C3b / C4b receptor ( CR 1 ) and comparison with H , C4b binding protein ( C4bp ) , and decay accelerating factor ( DAF ) . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Based on evidence suggesting that human leukocytes have factor 1 cofactor activity that is distinct from C3b / C4b receptor ( CR 1 ) , we purified the cofactor protein from several human leukocyte cell lines , and its structural and functional properties assessed . ^^^ This protein therefore shares some common properties characteristic to complement regulatory proteins , CR 1 , H , and C4b binding protein ( C4bp ) . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The isolated molecules were subjected to NaDodSO4 / PAGE , and autoradiographs of these gels indicated that C 3 binding proteins could be divided into three groups based on Mr : ( 1 ) gp 200 , an approximately 200 , 000 Mr molecule previously identified as the C3b / C4b receptor or CR 1 ; ( 2 ) gp 140 , an approximately 140 , 000 Mr molecule previously identified as the C3d receptor or CR 2 ; and ( 3 ) gp 45 70 , a heretofore unrecognized group of 45 , 000 70 , 000 Mr C 3 binding molecules . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The receptor for C3b and C4b complement receptor type 1 ( CR 1 , CD 35 ) is present on a variety of cell types including erythrocytes , phagocytic cells , B lymphocytes and a small subpopulation of T lymphocytes . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| However , no therapeutic agents that inhibit complement activation are available for human use . sCR 1 ( TP 10 , BRL 55736 ) is a recombinant , soluble human complement receptor 1 ( CR 1 ) molecule lacking transmembrane and cytoplasmic domains that inhibits C 3 and C 5 convertase activity by preferentially binding C4b and C3b . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Formation and function of the classical ( C4b , 2a ) and alternative ( C3b , Bb ) complement pathway C 3 convertases are regulated by the intrinsic lability of the enzymes , extrinsic decay by C4bp and H , cleavage of C4b and C3b by 1 , and by the inhibitory action of the C3b receptor molecule ( CR 1 ) . ^^^ In the present study , binding of C4Nef to the classical C 3 convertase was found to prevent decay of C4b , 2a by inputs of CR 1 that were at least 15 times the amount of CR 1 which inactivated 50 % unstabilized classical pathway C 3 convertase sites in 2 . 5 min . ^^^ CR 1 could however inhibit lysis of C4b , 2a ( C4Nef ) bearing cells in a dose dependent manner . ^^^ Because CR 1 is essential for degradation of C3b bound to immune complexes in whole blood , stabilization of C4b , 2a and C3b , Bb by C4Nef and C3Nef may alter in vivo processing of immune complexes in patients with nephritic factors . . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| CR 1 inhibits the consumption of C 3 by C 3 convertase EAC 142 and enhances the decay of C4b , 2a sites . ^^^ On a weight basis , CR 1 is approximately 5 10 times more active than C 4 binding protein , a serum inhibitor of C4b , 2a . ^^^ Therefore , it is likely that CR 1 and C 2 compete for a site on C4b . ^^^ At high concentrations , CR 1 alone has no irreversible effects on cell bound C4b . ^^^ In the fluid phase , CR 1 can function as a cofactor for the cleavage of the alpha ' chain of C4b by C3b / C4b inactivator . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Surface receptors specific for either the C4b ( CR 1 ) or C3d ( CR 2 ) component of complement were examined on the neoplastic cells from 30 cases of non Hodgkin ' s lymphoma of B cell origin and on cells derived from 9 normal lymphoid tissues . ^^^ Lymphocyte suspensions from non neoplastic peripheral blood , tonsils , and lymph node contained three categories of complement receptor lymphocytes ( CRL ) : cells with receptors for both C4b and C3d ( CR1+ , CR2+ ) ; cells with receptors for C4b but not C3d ( CR1+ , CR 2 ) , and cells with receptors for C3d but not C4b ( CR 1 , CR2+ ) . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| This study reports quantitative information on the concentration of complement receptor for C3b and C4b ( CR 1 ) on erythrocytes from normal individuals and patients with immune complex disease . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The main finding of this paper is that CR 1 , the membrane receptor for C3b and C4b , together with C3b / C4b inactivator ( 1 ) , degrades C3b bound to immune complexes ( C3b * ) . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| As it is not known why the strictly controlled C system starts to react against autologous heart tissue , we have analyzed the expression of various membrane regulators of C ( CR 1 , DAF , MCP , CD 59 , C 8 binding protein ) and the pattern of deposition of C components and plasma C regulators ( C4b binding protein and vitronectin ) in normal ( n = 7 ) and infarcted ( n = 13 ) human myocardium . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Comparison of the rabbit C4BP alpha chain sequence with other SCR containing C3b / C4b binding proteins revealed highest sequence similarities between the second SCRs in C4BP from rabbit , human and murine species and SCRs at corresponding position in complement receptor 1 ( CR 1 ) whereas in decay accelerating factor ( DAF ) , the third SCR was most similar . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The purpose of this study was to characterize the structure and function of the immune adherence receptor ( CR 1 , CD 35 , C3b / C4b receptor ) of primates . ^^^ The fact that these E proteins cross react with Ab to human CR 1 , bind homologous C3b and , in most cases , C4b , and for some species represent the only such protein expressed on their E identifies them as immune adherence receptors . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Quantitative analysis of C4b dimer binding to distinct sites on the C3b / C4b receptor ( CR 1 ) . ^^^ The binding reaction between CR 1 and soluble dimers of C4b ( C4b2 ) was analyzed using the native receptor on human erythrocytes and full length recombinant CR 1 expressed in stably transfected Chinese hamster ovary ( CHO ) cells . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Binding of C3b and C4b by the CR 1 like site in murine CR 1 . ^^^ We determined whether the six short consensus repeats ( SCRs ) that are appended to the amino terminus of murine CR 2 to form murine CR 1 contain a binding site for C4b in addition to that for C3b , and whether these sites overlap or are distinct . ^^^ These cell lines , and two others expressing full length human CR 1 and SCRs 8 11 of the C3b binding site of human CR 1 , respectively , were assessed for their capacity to form rosettes with sheep E bearing rat C4b or guinea pig C3b . ^^^ Therefore , murine CR 1 binds both C3b and C4b , and the sites for these ligands have similar , if not identical , amino and carboxyl terminal boundaries . . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Analysis of the functional domains of complement receptor type 1 ( C3b / C4b receptor ; CD 35 ) by substitution mutagenesis . ^^^ CR 1 4 , composed of eight and one half initial SCRs , carries site 1 , binds C4b , and is cofactor for C4b cleavage . ^^^ CR 1 4 ( 8 , 9 ) , obtained from CR 1 4 by converting site 1 to site 2 , binds iC3 / C3b and , unexpectedly , C4b . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| It regulates complement activation by proteolytic degradation of C3b or C4b in the presence of factor H , complement receptor type 1 , membrane cofactor protein or C4b binding protein as cofactor . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| E capture circulating IC via interaction between C3b and C4b sites , generated on the IC during activation of the complement cascade , and the complement receptor , type 1 ( CR 1 ) , expressed on E . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| In addition to its involvement in the processing and clearance of immune complexes with C3b or C4b on their surface , CR 1 acts as a cofactor for the proteolysis of C3b and C4b by Factor 1 . sCR 1 is a recombinant , soluble form of CR 1 which retains the cofactor activities of CR 1 , and is of potential therapeutic value for the suppression of complement mediated tissue damage in vivo . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Substitution of two amino acids confers C3b binding to the C4b binding site of CR 1 ( CD 35 ) . ^^^ It differs from the C4b binding site of Hu CR 1 only by two amino acids , Tyr for Ser 37 in CP 1 and Asp for Gly 79 in CP 2 . ^^^ To test this , using a truncated form of Hu CR 1 that has a binding site only for C4b , we made these additional constructs . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| A soluble deletion mutant of the human complement receptor type 1 , which lacks the C4b binding site , is a selective inhibitor of the alternative complement pathway . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Concomitant with the addition of human plasma , vehicle ( n = 13 ) , soluble complement receptor type 1 ( sCR 1 ) ( n = 10 ) , or sCR 1 [ desLHR A ] , a truncated version of sCR 1 that lacks the C4b binding region ( n = 10 ) was included in the perfusate . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| We now report that C1q binds specifically to human CR 1 ( CD 35 ) , the leukocyte C3b / C4b receptor , and the receptor on erythrocytes for opsonized immune complexes . ^^^ Thus , CR 1 is a cellular C1q receptor that recognizes all three complement opsonins , namely , C1q , C3b , and C4b . . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Expression of MHC class 1 , CD 16 ( low affinity Fc receptor for aggregated IgG ) , CD 32 ( low affinity Fc receptor for aggregated IgG ) , CD 64 ( high affinity receptor for IgG ) , CD11b ( receptor for complement component iC3b [ CR 3 ] ) , CD 35 ( receptor for complement components C3b and C4b [ CR 1 ] ) , and CD 36 ( non class A scavenger receptor ) was not specifically affected by hemozoin loading . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Complement receptor type one ( CR 1 ; CD 35 ) binds and processes C3b and C4b opsonized immune complexes and regulates complement activation . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Crry has been used because , similar to human soluble CR 1 , it demonstrates decay accelerating activity for both the classical and alternative pathways of complement as well as cofactor activity for factor 1 mediated cleavage of C3b and C4b . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Its cofactor activity for C4b cleavages was similar to that of soluble complement receptor type 1 . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| C1q and C4b bind simultaneously to CR 1 and additively support erythrocyte adhesion . ^^^ Titration of C1q alone , C4b alone , and C1q + C4b indicated that the two complement ligands were additive in their ability to support CR 1 mediated adhesion of E . ^^^ Analysis of binding to immobilized CR 1 using a BIAcore instrument documented that C1q , C4b , and C3b binding were independent events . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The lack of protection in Cr 2 ( / ) mice suggests that absence of CR 1 had no significant affect , considering its role in immune complex clearance , inhibition of C 3 and C 5 convertase and as receptor for C3b / C4b . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| The structure of the principal C3b / C4b binding site ( residues 901 1095 ) of CR 1 is reported , revealing three complement control protein modules ( modules 15 17 ) in an extended head to tail arrangement with flexibility at the 16 17 junction . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| As a receptor , CR 1 binds to C1q , other C opsonins ( C4b , C3b , iC3b ) and MBL , and as such , has been involved in promoting phagocytosis . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| A CR 1 polymorphism associated with constitutive erythrocyte CR 1 levels affects binding to C4b but not C3b . ^^^ In an ELISA comparing relative ligand binding differences , E CR 1 from individuals homozygous for the variant residues ( 643TT / 981HH ) exhibited greater binding to C4b , but not C3b , than homozygous wild type E CR 1 . ^^^ Analysis of single binding domain CR 1 constructs demonstrated that the 981H residue imparted this enhanced C4b binding . ^^^ These data suggest that the 981H residue compensates for low constitutive expression of E CR 1 in Caucasians by enhancing C4b binding . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| It circulates in an active form and has very restricted specificity , cleaving only C3b or C4b in the presence of a cofactor such as factor H ( fH ) , complement receptor type 1 , membrane cofactor protein , or C 4 binding protein . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Immune complexes activate the classical pathway of complement resulting in the covalent deposition of fragments of the third ( C3b ) and fourth ( C4b ) components of complement , thus opsonizing the complexes for uptake by CD 35 found on human erythrocytes . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Then , a total of 45 antibodies were neutralized with sCR 1 , including the following : one each of anti Cr ( a ) , Dr ( a ) , Do ( b ) , Hy , Ge , Jr ( a ) , Sc 1 , Jk ( a ) , Cs ( a ) , and Kp ( b ) ; two each of anti Lu ( b ) , Yt ( a ) , and JMH ; three each of anti McC ( a ) , Rg , and Sl ( a ) ; and four each of anti Ch , Kn ( a ) , Yk ( a ) , Kn / McC . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| CR 1 is the most versatile inhibitor of both classical and alternative pathway C 3 and C 5 convertases due to its decay accelerating activity and co factor activity for C3b / C4b cleavage . ^^^ Moreover , CR 1 plays a major role in immune complex clearance due to its high affinity for C3b and C4b . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| Complement receptor type 1 ( CR 1 ) is a membrane glycoprotein that acts as a receptor for the C3b , iC3b and C4b fragments of complement . ^^^ Complement receptor type 1 ( CR 1 ) is a membrane glycoprotein that acts as a receptor for the C3b , iC3b and C4b fragments of complement . ^^^ |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|
| Interacting proteins: P0C0L4 and P17927 |
Pubmed |
SVM Score :0.0 |
| NA |
|