The carboxyl-terminal domains of gp130-related cytokine receptors are necessary for suppressing embryonic stem cell differentiation - Involvement of STAT3
The carboxyl-terminal domains of gp130-related cytokine receptors are necessary for suppressing embryonic stem cell differentiation - Involvement of STAT3
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DOI：
10.1074/jbc.274.14.9729
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发表时间：
1999-04-02
影响因子：
4.8
通讯作者：
Dunn, AR
中科院分区：
文献类型：
--
作者：
Ernst, M;Novak, U;Dunn, AR
对白血病抑制因子（LIF）/白细胞介素6细胞因子家族的细胞类型特异性应答是通过LIF受体α链（LIFR α）与信号转导物gp 130或两个gp 130分子的二聚化，随后激活JAK/STAT和Ras/促分裂原活化蛋白激酶级联介导的。为了分别分析gp 130和LIFR α的作用，在胚胎干（ES）细胞中表达由粒细胞集落刺激因子受体（GCSF-R）的细胞外结构域和gp 130或LIFR α的细胞质结构域的各种突变形式组成的嵌合分子，以测试对分化的抑制，或在因子依赖性浆细胞瘤细胞系中以评估增殖的诱导。磷酸酶（SHP 2）结合位点下游的羧基末端结构域被激活，用于丝裂原活化蛋白激酶活化和增殖信号的转导。此外，羧基端截短突变体，缺乏完整的盒3同源结构域显示减少STAT 3激活，未能诱导Hck激酶活性和抑制ES细胞分化。此外，STAT 3反义寡核苷酸损害LIF依赖的分化抑制。在GSCF-R的Box 3区域内的酪氨酸残基的取代废除了受体介导的分化抑制，而不影响增殖信号的转导。因此，LIFR α、gp 130和GCSF-R内不同的胞质结构域表达增殖和分化抑制信号。
Cell type-specific responses to the leukemia inhibitory factor (LIF)/interleukin 6 cytokine family are mediated by dimerization of the LIF receptor alpha-chain (LIFR alpha) with the signal transducer gp130 or of two gp130 molecules followed by activation of the JAK/STAT and Ras/mitogen-activated protein kinase cascades. In order to dissect the contribution of gp130 and LIFR alpha individually, chimeric molecules consisting of the extracellular domain of the granulocyte colony stimulating factor receptor (GCSF-R) and various mutant forms of the cytoplasmic domains of gp130 or LIFR alpha were expressed in embryonic stem (ES) cells to test for suppression of differentiation, or in a factor-dependent plasma cytoma cell line to assess for induction of proliferation. Carboxyl-terminal domains downstream of the phosphatase (SHP2)-binding sites were dispensable for mitogen-activated protein kinase activation and the transduction of proliferative signals. Moreover, carboxyl-terminal truncation mutants which lacked intact Box 3 homology domains showed decreased STAT3 activation, failed to induce Hck kinase activity and suppress ES cell differentiation. Moreover, STAT3 antisense oligonucleotides impaired LIF-dependent inhibition of differentiation. Substitution of the tyrosine residue within the Box 3 region of the GSCF-R abolished receptor-mediated suppression of differentiation without affecting the transduction of proliferative signals. Thus, distinct cytoplasmic domains within the LIFR alpha, gp130, and GCSF-R transduce proliferative and differentiation suppressing signals.