Tyrosyl phosphorylation and DNA binding activity of signal transducers and activators of transcription (STAT) proteins in hematopoietic cell lines transformed by Bcr/Abl.
Tyrosyl phosphorylation and DNA binding activity of signal transducers and activators of transcription (STAT) proteins in hematopoietic cell lines transformed by Bcr/Abl.
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DOI：
10.1084/jem.183.3.811
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发表时间：
1996-03-01
影响因子：
15.3
通讯作者：
Griffin, JD
中科院分区：
文献类型：
--
作者：
Carlesso, N;Frank, DA;Griffin, JD
Bcr/Abl 是一种嵌合癌基因，可引起急性和慢性人类白血病。与 c-Abl 相比，Bcr/Abl 编码的蛋白表现出更高的激酶活性，但转化机制很大程度上未知。 Bcr/Abl 的一些生物学效应与造血细胞因子的生物学效应重叠，特别是白细胞介素 3 (IL-3)。这些作用包括有丝分裂、提高存活率和增强嗜碱性分化。因此，有人提出p210Bcr/Abl和IL-3受体可能激活一些常见的信号转导途径。 IL-3 信号转导的一个重要途径涉及 Janus 家族激酶 (JAK) 的激活以及随后的 STAT 蛋白（信号转导子和转录激活子）的酪氨酰磷酸化。该途径将生长因子受体与基因转录直接联系起来。我们分析了一系列由 Bcr/Abl 或其他癌基因转化的白血病细胞系中的 JAK 激活、STAT 蛋白磷酸化以及含有 STAT 蛋白的特异性 DNA 结合复合物的形成。我们还在 Bcr/Abl 温度敏感 (ts) 突变体转化的细胞系中检查了这些事件，其中 Abl 的激酶活性可以受到调节。发现 STAT1 和 STAT5 在 Bcr/Abl 转化的 32D、Ba/F3 和 TF-1 细胞中被组成型磷酸化，但在不存在 IL-3 的未转化亲本细胞系中则不会被磷酸化。在表达 Bcr/Abl 癌基因的人白血病细胞系 K562 和 BV173 中也观察到了 STAT1 和 STAT5 的磷酸化，但在几种 Bcr/Abl 阴性白血病细胞系中未观察到 STAT1 和 STAT5 的磷酸化。 STAT1 和 STAT5 的磷酸化直接归因于 Bcr/Abl 的酪氨酸激酶活性，因为它可以通过表达 Bcr/Abl ts 突变体的细胞的温度变化而激活或失活。在所有 Bcr/Abl 转化细胞系中均检测到 DNA-STAT 复合物，并且它们被针对 STAT1 和 STAT5 的抗体超移。 32Dp210Bcr/Abl 细胞中的 DNA-STAT 复合物与 IL-3 刺激后形成的 DNA-STAT 复合物相似，但不相同。有趣的是，JAK 激酶（JAK1、JAK2、JAK3 和 Tyk2）在 Bcr/Abl 阳性细胞中并未持续激活。这些数据表明 STAT 可以直接被 Bcr/Abl 激活，可能绕过 JAK 家族激酶激活。总的来说，我们的结果表明了一种新的机制，可能有助于 Bcr/Abl 转化的一些主要生物效应。
Bcr/Abl is a chimeric oncogene that can cause both acute and chronic human leukemias. Bcr/Abl-encoded proteins exhibit elevated kinase activity compared to c-Abl, but the mechanisms of transformation are largely unknown. Some of the biological effects of Bcr/Abl overlap with those of hematopoietic cytokines, particularly interleukin 3 (IL-3). Such effects include mitogenesis, enhanced survival, and enhanced basophilic differentiation. Therefore, it has been suggested that p210Bcr/Abl and the IL-3 receptor may activate some common signal transduction pathways. An important pathway for IL-3 signaling involves activation of the Janus family kinases (JAKs) and subsequent tyrosyl phosphorylation of STAT proteins (signal transducers and activators of transcription). This pathway directly links growth factor receptors to gene transcription. We analyzed JAK activation, STAT protein phosphorylation, and the formation of specific DNA-binding complexes containing STAT proteins, in a series of leukemia cell lines transformed by Bcr/Abl or other oncogenes. We also examined these events in cell lines transformed by a temperature sensitive (ts) mutant of Bcr/Abl, where the kinase activity of Abl could be regulated. STAT1 and STAT5 were found to be constitutively phosphorylated in 32D, Ba/F3, and TF-1 cells transformed by Bcr/Abl, but not in the untransformed parental cell lines in the absence of IL-3. Phosphorylation of STAT1 and STAT5 was also observed in the human leukemia cell lines K562 and BV173, which express the Bcr/Abl oncogene, but not in several Bcr/Abl- negative leukemia cell lines. Phosphorylation of STAT1 and STAT5 was directly due to the tyrosine kinase activity of Bcr/Abl since it could be activated or deactivated by temperature shifting of cells expressing the Bcr/Abl ts mutant. DNA-STAT complexes were detected in all Bcr/Abl- transformed cell lines and they were supershifted by antibodies against STAT1 and STAT5. DNA-STAT complexes in 32Dp210Bcr/Abl cells were similar, but not identical, to those formed after IL-3 stimulation. It is interesting to note that JAK kinases (JAK1, JAK2, JAK3, and Tyk2) were not consistently activated in Bcr/Abl-positive cells. These data suggest that STATs can be activated directly by Bcr/Abl, possibly bypassing JAK family kinase activation. Overall, our results suggest a novel mechanism that could contribute to some of the major biological effects of Bcr/Abl transformation.
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影响因子：
11.4
作者：
MATSUGUCHI, T;INHORN, RC;GRIFFIN, JD
通讯作者：
GRIFFIN, JD
影响因子：
20.3
作者：
LOZZIO, CB;LOZZIO, BB
通讯作者：
LOZZIO, BB
影响因子：
64.5
作者：
FU, XY
通讯作者：
FU, XY
DOI：
10.1073/pnas.92.17.7779
发表时间：
1995-08-15
影响因子：
11.1
作者：
FRANK, DA;ROBERTSON, MJ;GREENBERG, ME
通讯作者：
GREENBERG, ME
影响因子：
5.3
作者：
KONOPKA, JB;WITTE, ON
通讯作者：
WITTE, ON