1999年8月1日 · Lyn is hyperphosphorylated and activated in a CD45-deficient clone from WEHI-231 cells. A, WEHI-231 and its CD45-deficient clone (10-5) were either stimulated with 25 μg/ml anti-IgM Ab for 1 min (+) or unstimulated (−), solubilized, and immunoprecipitated with protein G-Sepharose coated with anti-Lyn Ab.The immunoprecipitates were subjected to SDS-PAGE analysis and Western blotting with ...

2005年1月1日 · Lyn can be activated by dephosphorylation of the C-terminal regulatory tyrosine by CD45. CD45 is shown within the lipid raft and acting to dephosphorylate Y508 for graphic purposes. Its location varies over time and it is also able to dephosphorylate Y397, inhibiting SFK activity (Ashwell and D'Oro, 1999) .

1999年8月1日 · Using CD45-deficient clones from the immature B cell line, WEHI-231, we previously demonstrated that CD45 selectively dephosphorylates the Src-family protein tyrosine kinase Lyn and inhibits its kinase activity. To further define the mechanisms of CD45 action on Lyn, we metabolically labeled Lyn fro …

Here, we focus on the role of three phosphatases, CD45, CD148, and LYP/PEP, which are critical regulators of src family kinase activity in hematopoietic cells. We review our current understanding of their structures, expression, functions in different hematopoietic cell subsets, regulation, and putative roles in disease.

2004年2月15日 · CD45 is a key protein tyrosine phosphatase regulating Src-family protein tyrosine kinases (Src-PTKs) in lymphocytes; precisely how it exerts its effect remains controversial, however. We previously demonstrated that CD45 negatively regulates Lyn in the WEHI-231 B-cell line.

2013年3月15日 · We found that CD45 −/− Lyn −/− double-mutant animals phenocopy CD45 −/− animals and effectively rescue the Lyn −/− phenotype (Fig. 4B–D, Supplemental Fig. 4). In contrast, H/H Lyn −/− double-mutant animals exhibit a synergistic phenotype with a reduction in B cells more severe than either mutant alone ( Fig. 4B–D ...

The results clearly demonstrated that among PTKs examined (Lyn, Lck, and Syk), only Lyn kinase is dysregulated in the absence of CD45 such that without B cell antigen receptor ligation, Lyn is hyperphosphorylated and activated in CD45-negative clones. Thus, Lyn seems to be a selective in vivo substrate for CD45 in immature B cells.

1997年6月1日 · In lymphocytes, CD45 is a leukocyte-specific transmembrane protein tyrosine phosphatase that activates Src family kinases associated with B-cell and T-cell antigen receptor signaling by constitutive dephosphorylation of the inhibitory carboxy-terminal tyrosine phosphorylation site.

1996年5月1日 · These novel results propose a role for these vesicles in signal transduction mechanisms of normal and neoplastic hematopoietic cells. In support of this hypothesis, we further observed that molecules participating in B- and T-cell receptor activation cofractionate in the LDTI fractions, CD45/lyn (B cells) and CD45/lck/CD4 (T cells).

2008年6月15日 · Analysis of DCs from CD45-positive and CD45-null mice revealed that CD45 is not required for the development of DCs but does influence DC maturation induced by TLR agonists. CD45 affected the phosphorylation state of Lyn, Hck, and Fyn in bone marrow-derived DCs and dysregulated LPS-induced Lyn activation.