Pubmed abstracts for Protein-Protein Interaction search result :


Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
CD 22 is a B cell membrane glycoprotein that , upon Ag receptor engagement , becomes rapidly tyrosyl phosphorylated and associates with several signaling molecules including Lyn , Syk , PLCgamma 1 , and the protein tyrosine phosphatase , SHP 1 . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Inhibition of the B cell by CD 22 : a requirement for Lyn . ^^^ Mice in which the Lyn , Cd 22 , or Shp 1 gene has been disrupted have hyperactive B cells and autoantibodies . ^^^ We find that in the absence of Lyn , the ability of CD 22 to become tyrosine phosphorylated after ligation of mIg , to recruit SHP 1 , and to suppress mIg induced elevation of intracellular [ Ca2+ ] is lost . ^^^ Therefore , Lyn is required for the SHP 1 mediated B cell suppressive function of CD 22 , accounting for similarities in the phenotypes of these mice . . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Here we show that tyrosine phosphorylation of FcgammaRIIB and CD 22 coreceptors , which are important for feedback suppression of BCR induced signaling , was severely impaired in lyn / B cells upon their coligation with the BCR . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Polygenic autoimmune traits : Lyn , CD 22 , and SHP 1 are limiting elements of a biochemical pathway regulating BCR signaling and selection . ^^^ As in invertebrates , genetic effects of loci with only one functional allele can be used to analyze signaling networks in mice , demonstrating that negative regulation of the BCR is a complex quantitative trait in which Lyn , the coreceptor CD 22 , and the tyrosine phosphatase SHP 1 are each limiting elements . ^^^ The biochemical basis of this complex trait involves a pathway requiring Lyn to phosphorylate CD 22 and recruit SHP 1 to the CD22 / BCR complex . . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
The regulation of calcium responses involves a network of tyrosine kinases ( e . g . lyn , syk ) , tyrosine or lipid phosphatases ( CD 45 , SHP 1 , SHIP ) , and accessory molecules ( CD21 / CD19 , CD 22 , FcR gamma 2b ) . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
As the co receptors Fc gamma RIIb 1 and CD 22 have been shown to be negative regulators of BCR signaling , we have now examined their functional roles in lyn / B cells . ^^^ In contrast , tyrosine phosphorylation of CD 22 was greatly decreased in lyn / B cells , correlating with the inability of CD 22 to downregulate the BCR induced calcium response in these cells . ^^^ Surprisingly , CD 22 remains capable of regulating the ERK 2 and JNK pathways in lyn / B cells , which may relate to the small residual increase in BCR induced CD 22 phosphorylation . ^^^ In contrast , Lyn plays a particularly important role in the tyrosine phosphorylation of CD 22 and in the consequent inhibition of BCR induced calcium influx . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
In contrast , some aspects of inhibition by CD 22 appear to be almost completely dependent upon Lyn and Fc gamma RIIb 1 inhibition is also diminished in the absence of Lyn . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
It has been reported that BCR mediated signaling in B 1 cells is negatively regulated by signals from CD 22 , CD 5 and CD 72 co receptors , and that Lyn kinase plays a crucial role in tyrosine phosphorylation of immunoreceptor tyrosine based inhibitory motifs on the CD 22 and CD 72 , which recruits SHP 1 to the BCR complex . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
BACKGROUND : To better understand the molecular background of B cell overactivity characterizing systemic lupus erythematosus ( SLE ) , we examined the expression of the CD 22 co receptor and of kinase Lyn , which are involved in signaling inhibitory pathways , in B cells from patients with SLE . ^^^ RESULTS : Expression of B cell surface CD 22 was intact in patients with SLE , but expression of the B cell kinase Lyn was significantly decreased in resting , as well as in anti sIgM stimulated B cell enriched cell lysates obtained from 66 % of patients with SLE . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
CD 19 amplification of Lyn activity leads to processive phosphorylation of CD 19 and downstream substrates including CD 22 . ^^^ CD19 / Lyn complex formation also regulates phosphorylation of CD 22 and FcgammaRIIB , which inhibit B cell signal transduction through the recruitment of the SHPI and SHIP phosphatases . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Individually both Lyn and Syk are required for maximal phosphorylation of CD 22 following ligation of the BCR , and together Lyn and Syk are required for all of the constitutive and induced tyrosine phosphorylation of CD 22 . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Although simultaneous CD 19 and BCR engagement significantly enhanced CD19 / Lyn complex formation and [ Ca ( 2+ ) ] ( 1 ) responses , downstream tyrosine phosphorylation of CD 22 and multiple other cellular proteins was inhibited , as was SHP 1 recruitment to phosphorylated CD 22 . ^^^ Because CD 19 and Lyn expression are genetically titrated in B cells , CD 19 engagement may augment BCR induced [ Ca ( 2+ ) ] ( 1 ) responses by sequestering the available pool of functional Lyn away from downstream negative regulatory proteins such as CD 22 . ^^^ Consistent with this , simultaneous CD 19 engagement did not further enhance the BCR induced [ Ca ( 2+ ) ] ( 1 ) responses of Lyn or CD 22 deficient B cells . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
This autoimmunity may result from loss of a feedback inhibitory pathway in which Lyn phosphorylates CD 22 , triggering recruitment of the tyrosine phosphatase SHP 1 to the plasma membrane , which then dampens BCR signaling . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
CD 19 ( / ) B cells were normal for increased Lyn kinase activity after BCR ligation , inhibition of BCR mediated calcium flux after CD 22 coligation , and inhibition of extracellular signal regulated kinase phosporylation after FcgammaRIIB coligation . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Lyn ( up / up ) B cells are characterized by the constitutive phosphorylation of negative regulators of B cell antigen receptor ( BCR ) signaling including CD 22 , SHP 1 , and SHIP 1 , and display attributes of lymphocytes rendered tolerant by constitutive engagement of the antigen receptor . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Analysis of Lyn / CD22 double deficient B cells in vivo demonstrates Lyn and CD 22 independent pathways affecting BCR regulation and B cell survival . ^^^ CD 22 recruits a variety of signal enhancers at the same time as Lyn dependent phosphorylation leads to the binding of the inhibitory phosphatase SHP 1 . ^^^ To assess the relative importance of Lyn and CD 22 dependent and independent pathways , we generated Lyn and CD 22 single deficient mice and Lyn / CD22 double deficient mice expressing the MD 4 immunoglobulin transgene against hen egg lysozyme ( IgHEL ) . ^^^ This genetic approach has enabled us to compare the contributions of Lyn and CD 22 to B cell development in vivo , independent of BCR specificity and in the presence and absence of self antigen . ^^^ Our results show that although the effects of Lyn are dominant in negative regulation of B cell hyperactivity , Lyn and CD 22 have independent and additive effects on B cell survival . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
By contrast , CD19 / CD21 ligation using higher concentrations of SA C3dg significantly inhibited BCR induced [ Ca2+ ] 1 responses and inhibited CD 19 , Lyn , CD 22 , and Syk phosphorylation . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
In this review , we discuss the potential role of molecules involved in altered B cell longevity , especially molecules involved in apoptosis ( bcl 2 , bcl 10 , mutations in the Fas / Fas L pathway ) , as well as molecules that might alter activation thresholds of B cells ( CD 19 , CD 21 , CD 22 , lyn , SHP , SHIP 1 ) in the development of autoimmunity . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
Diminished immune responses due to ST6Gal 1 deficiency further correlate with constitutive recruitment of Shp 1 to CD 22 in unstimulated B cells independent of Lyn tyrosine kinase activity and prevent autoimmune disease pathogenesis in the Lyn deficient model of systemic lupus erythematosus , resulting in a significant extension of life span . ^^^
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
NA
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
NA
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
NA
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
NA
Interacting proteins: P20273 and P07948 Pubmed SVM Score :0.0
NA