B cell signaling molecules which regulated by protein tyrosine phosphatase CD45

蛋白酪氨酸磷酸酶CD45调节的B细胞信号分子

• 批准号: 11680645
• 负责人: KATAGIRI Tatsuo
• 金额: $ 2.3万
• 依托单位: Tokyo Metropolitan Organization for Medical Research
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680645/
• 关键词: CD45; BCR signal; Src-family PTK; Lyn; Fyn; protein tyrosine phosphatase (PTP); Protein tyrosine kinase (PTK); raft; ラフト; 成熟B細胞

CD45 is a critical regulator of T and B cell activation. However, there have been conflicting results as to the mode of CD45 action.1. To obtain some insights into this problem, we tried to identify substrate PTKs for CD45 in B cells and to determine the dephosphory lation sites of the Src-family PTKs. The results demonstrated that in CD45-deficient clones from the immature B cell line, Lyn was selectively hyperphosphorylated and activated in the absence of B cell receptor (BCR) ligation. CD45 constitutively inactivates Lyn by dephosphorylating both the positive (394) and negative (508) tyrosine residues (J.Immunol. 163 : 1321-1326, 1999).2. We also examined contribution made by CD45 to BCR-induced activation of mitogen-activated protein kinase (MAPK) family members. We found that CD45 regulated BCR-induced c-Jun NH2-terminal kinase (JNK) and p38. Interestingly, the regulation was depend on B cell differentiation level (FEBS Lett. 490 : 97-101, 2001).3. CD45 exerts a decisive effect on selective sets of CD40-mediated signaling pathway, dictating B cell fate (J.Biol. Chem. 276 : 8550-8556, 2001).4. To elucidate the molecular basis of these observations, we are now trying to determine the precise localization of CD45 with Src-family PTK, we utilized glycolipid-enriched membrane fraction (GEM), commonly referred to as lipid raft, as a marker. The preliminary results revealed that CD45 is present in the raft before BCR ligation and is sequestered from the raft after stimulation. These results suggest that CD45 constitutively associated with the raft inactivates, Src-family PTK and BCR ligation somehow sequesters CD45 from the raft, thereby initiating activation cascades.Thus, we are in the process of revealing the regulatory mechanism of BCR signals by CD45 on lipid raft.

CD45是T、B细胞活化的重要调节因子。然而，关于CD45行动的模式1，出现了相互矛盾的结果。为了对这个问题有一些了解，我们试图在B细胞中鉴定CD45的底物PTKs，并确定Src家族PTKs的脱磷位置。结果表明，在未成熟B细胞系的CD45缺陷克隆中，Lyn选择性过度磷酸化并在没有B细胞受体(BCR)连接的情况下被激活。CD45通过去磷酸化阳性(394)和阴性(508)酪氨酸残基使Lyn失活(J.163：1321-1326,1999)我们还研究了CD45在BCR诱导的丝裂原活化蛋白激酶(MAPK)家族成员激活中的作用。我们发现CD45调控BCR诱导的c-jun氨基末端激酶(JNK)和p38。有趣的是，这种调节依赖于B细胞分化水平(FEBS Lett)。490：97-101,2001).CD45在CD40介导的信号通路的选择性集合中起决定性作用，决定B细胞的命运(J.Biol。化学。276：8550-8556,2001).为了阐明这些观察的分子基础，我们现在正试图用Src家族PTK来确定CD45的精确定位，我们使用了糖脂富集膜部分(GEM)作为标记，通常被称为脂筏。初步结果表明，CD45在BCR结扎前存在于筏中，刺激后CD45从筏中分离出来。这些结果表明，CD45与RAFT结合失活，Src家族PTK和BCR连接以某种方式将CD45从RAFT中隔离出来，从而启动激活级联反应，从而揭示CD45对脂筏上BCR信号的调节机制。

项目成果

Arimura Y, Ogimoto M, Mitomo K, Katagiri T, Yamamoto K, Volarevic S, Mizuno K & Yakura H: "CD45 is required for CD40-induced inhibition of DNA synthesis and regulation of c-Jun NH2-terminal kinase and p38 in BAL-17 B cells."J.Biol. Chem.. 276. 8550-8556 (

Arimura Y、Ogimoto M、Mitomo K、Katagiri T、Yamamoto K、Volarevic S、Mizuno K

Ogimoto M, Arimura Y, Katagiri T, Mitomo K, Woodgett JR, Nebreda AR, Mizuno K & Yakura H: "Opposing regulation of B cell receptor-induced activation of mitogen-activated protein kinases by CD45."FEBS Lett. 490. 97-101 (2001)

荻本 M、Arimura Y、Katagiri T、Mitomo K、Woodgett JR、Nebreda AR、Mizuno K

Hasegawa Kiminori: "Requirement of PEST domain tyrosine phosphatase PEP in B cell antigen receptor-induced growth arrest and apoptosis."Eur J Immunol. 29号. 887-896 (1999)

Hasekawa Kiminori：“B 细胞抗原受体诱导的生长停滞和细胞凋亡中 PEST 结构域酪氨酸磷酸酶 PEP 的要求。”Eur J 免疫学杂志 29. 887-896 (1999)

Katagiri T, Ogimoto M, Hasegawa K, Arimura Y, Mitomo K, Okada M, Clark MR, Mizuno K & Yakura H: "CD45 negatively regulates Lyn activity by dephosphorylating both positive and negative regulatory tyrosine residues in immature B cells."J.Immunol.. 163. 1321

片桐 T、荻本 M、长谷川 K、Arimura Y、Mitomo K、冈田 M、克拉克 MR、水野 K

Kumanogoh A, Watanabe C, Lee I, Wang X, Shi W, Araki H, hirata H, Iwahor K, Uchida J, Yasui T, Matsumoto M, Yoshida K, Yakura H, Pan C, Parnes JR & Kikkutani Hi: "Identification of CD72 as a lymphocyte receptor for the class IV semaphorin CD100 : AΛnovel

Kumanogoh A、Watanabe C、Lee I、Wang X、Shi W、Araki H、hirata H、Iwahor K、Uchida J、Yasui T、Matsumoto M、Yoshida K、Yakura H、Pan C、Parnes JR 和 Kikkutani Hi：“识别CD72 作为 IV 类信号蛋白 CD100 的淋巴细胞受体 : AΛnovel