The transcription factor PU.1 is involved in macrophage proliferation
The transcription factor PU.1 is involved in macrophage proliferation
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DOI：
10.1084/jem.184.1.61
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发表时间：
1996-07-01
影响因子：
15.3
通讯作者：
Maki, RA
中科院分区：
文献类型：
--
作者：
Celada, A;Borras, FE;Maki, RA
PU.1 是一种组织特异性转录因子，在造血谱系细胞（包括巨噬细胞、粒细胞和 B 淋巴细胞）中表达。与对照相比，用反义PU.1表达构建体转染或用反义寡核苷酸处理的骨髓源性巨噬细胞显示增殖减少。相反，用正义PU.1表达构建体转染的骨髓巨噬细胞表现出增强的巨噬细胞集落刺激因子（M-CSF）依赖性增殖。有趣的是，PU.1 的有义或反义构建体对 M-C:SF 独立细胞系的增殖没有影响，表明该反应是 M-CSF 依赖性的。转染有义PU.1或反义PU.1构建体的巨噬细胞分别显示M-CSF受体表面表达水平升高或降低，这一发现进一步支持了这一点。增殖的增强似乎对 PU.1 具有选择性，因为用 ets 家族的其他几个成员（包括 ets -2 和 fli-1）转染没有效果。还测试了 PU.1 的各种突变体影响巨噬细胞增殖的能力。当用表达 PU.1 DNA 结合结构域的构建体转染细胞时，发现巨噬细胞增殖减少。 PU.1 蛋白的 PEST（富含脯氨酸、谷氨酸、丝氨酸和苏氨酸的区域）序列是 B 细胞中蛋白质-蛋白质相互作用的重要结构域，当将含有减去 PEST 结构域的 PU.1 的表达构建体转染到骨髓来源的巨噬细胞中时，发现对 PU.1 增强的巨噬细胞增殖没有影响。在体内，PU.1 在几个丝氨酸残基上被磷酸化。含有五个丝氨酸突变的 PU.1 的质粒的转染表明，只有位置 41 和 45 对于增强巨噬细胞增殖至关重要。我们得出结论，PU.1 对于 M-CSF 依赖性巨噬细胞增殖是必需的。该转录因子的增殖相关靶标之一可能是 M-CSF 受体。
PU.1 is a tissue-specific transcription factor that is expressed in cells of the hematopoietic lineage including macrophages, granulocytes, and B lymphocytes. Bone marrow-derived macrophages transfected with an antisense PU.1 expression construct or treated with antisense oligonucleotides showed a decrease in proliferation compared with controls. In contrast, bone marrow macrophages transfected with a sense PU.1 expression construct displayed enhanced macrophage colony-stimulating factor (M-CSF)-dependent proliferation. Interestingly, there was no effect of sense or antisense constructs of PU.1 on the proliferation of the M-C:SF-independent cell line, suggesting that the response was M-CSF dependent. This was further supported by the finding that macrophages transfected with :I sense or an antisense PU.1 construct showed, respectively, an increased or a reduced level of surface expression of receptors for M-CSF. The enhancement of proliferation seems to be selective for PU.1, since transfections with several other members of the ets family, including ets -2 and fli-1, had no effect. Various mutants of PU.1 were also tested for their ability to affect macrophage proliferation. A reduction in macrophage proliferation was found when cells were transfected with a construct in which the DNA-binding domain of PU.1 was expressed. The PEST (proline-, glutamic acid-, serine-, and threonine-rich region) sequence of the PU.1 protein, which is an important domain for protein-protein interactions in B cells, was found to have no influence on PU.1-enhanced macrophage proliferation when an expression construct containing PU.1 minus the PEST domain was transfected into bone marrow-derived macrophages. In vivo, PU.1 is phosphorylated on several serine residues. The transfection of plasmids containing PU.1 with mutations at each of five serines showed that only positions 41 and 45 are critical for enhanced macrophage proliferation. We conclude that PU.1 is necessary for the M-CSF-dependent proliferation of macrophages. One of the proliferation-relevant targets of this transcription factor could be the M-CSF receptor.