Anti-immunoglobulin M activates nuclear calcium/calmodulin-dependent protein kinase II in human B lymphocytes.
Anti-immunoglobulin M activates nuclear calcium/calmodulin-dependent protein kinase II in human B lymphocytes.
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DOI：
10.1084/jem.182.6.1943
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发表时间：
1995-12-01
影响因子：
15.3
通讯作者：
Bomsztyk, Karol
中科院分区：
文献类型：
--
作者：
Valentine, Mary A.;Czernik, Andrew J.;Rachie, Nisa;Hidaka, Hiroyoshi;Fisher, Constance L.;Cambier, John C.;Bomsztyk, Karol
我们和其他人之前已经证明，在 B 淋巴细胞上连接免疫球蛋白 (Ig) M 后，核蛋白 Ets-1 以钙依赖性方式磷酸化。由于这种磷酸化与蛋白激酶 C 活性无关，因此我们测试了钙/钙调蛋白依赖性蛋白激酶（CaM 激酶）是否可能在细胞内游离钙浓度升高后磷酸化 Ets-1 蛋白。 Ets-1 的去磷酸化形式已被证明可以与染色质结合，这表明在细胞核中应该可以检测到起作用的激酶。我们从两种人 B 细胞系中制备了核提取物，其中细胞内游离钙水平的增加与 Ets-1 蛋白磷酸化的增加相关。在存在和不存在 CaM 激酶家族特异性抑制剂 KN-62 的情况下，使用合成肽底物测定 CaM 激酶的活性。用抗 IgM 刺激细胞会导致核激酶活性增加，该核激酶可以磷酸化肽，并且该活性被 10 microM KN-62 降低。使用 CaM 激酶 II 特异性抗体预吸附的裂解物中激酶活性降低。来自用离子霉素或抗 IgM 孵育的细胞的 Ets-1 蛋白的二维磷酸肽图谱包含两种独特的磷酸肽，而未经处理的细胞中不存在这种肽。将分离的 Ets-1 蛋白与纯化的 CaM 激酶 II 一起孵育，会产生肽的磷酸化，其迁移方式与与抗 IgM 或离子霉素孵育的细胞中发现的肽相同。这些数据表明 B 淋巴细胞上抗原受体的信号转导模型，其中细胞内游离钙的增加可以快速激活核 CaM 激酶 II，可能导致 DNA 结合蛋白的磷酸化和调节。
We and others have previously shown that the nuclear protein, Ets-1, is phosphorylated in a calcium-dependent manner after ligation of immunoglobulin (Ig) M on B lymphocytes. As this phosphorylation was independent of protein kinase C activity, we tested whether a calcium/calmodulin-dependent protein kinase (CaM kinase) might phosphorylate the Ets-1 protein after elevation of intracellular free calcium concentrations. The dephosphorylated form of Ets-1 has been shown to bind to chromatin, suggesting that the operative kinase should be detectable in the nucleus. We prepared nuclear extracts from two human B cell lines in which increased intracellular free calcium levels correlated with increased phosphorylation of the Ets-1 protein. Activity of the CaM kinases was determined using a synthetic peptide substrate both in the absence and presence of an inhibitor specific for the CaM kinase family, KN-62. Stimulation of cells with anti-IgM led to increased activity of a nuclear kinase that could phosphorylate the peptide, and this activity was reduced by 10 microM KN-62. Kinase activity was reduced in lysates preadsorbed using an antibody specific for CaM kinase II. Two-dimensional phosphopeptide maps of the Ets-1 protein from cells incubated with ionomycin or anti-IgM contained two unique phosphopeptides that were absent in untreated cells. Incubation of isolated Ets-1 protein with purified CaM kinase II produced phosphorylation of peptides that migrated identically to those found in cells incubated with either anti-IgM or ionomycin. These data suggest a model of signal transduction by the antigen receptor on B lymphocytes in which increased intracellular free calcium can rapidly activate nuclear CaM kinase II, potentially resulting in phosphorylation and regulation of DNA-binding proteins.
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DOI：
10.1073/pnas.89.4.1291
发表时间：
1992-02-15
影响因子：
11.1
作者：
DUDEK, H;TANTRAVAHI, RV;REDDY, EP
通讯作者：
REDDY, EP
DOI：
10.1073/pnas.83.6.1613
发表时间：
1986-03-01
影响因子：
11.1
作者：
SCOTT, JD;GLACCUM, MB;KREBS, EG
通讯作者：
KREBS, EG
DOI：
10.1073/pnas.92.2.492
发表时间：
1995-01-17
影响因子：
11.1
作者：
RON, D;MOCHLYROSEN, D
通讯作者：
MOCHLYROSEN, D
影响因子：
14.9
作者：
DIGNAM, JD;LEBOVITZ, RM;ROEDER, RG
通讯作者：
ROEDER, RG
影响因子：
64.8
作者：
BENFENATI, F;VALTORTA, F;CZERNIK, AJ
通讯作者：
CZERNIK, AJ