Differential stimulation of c-Kit mutants by membrane-bound and soluble Steel Factor correlates with leukemic potential
Differential stimulation of c-Kit mutants by membrane-bound and soluble Steel Factor correlates with leukemic potential
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DOI：
10.1182/blood.v96.12.3734.h8003734_3734_3742
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发表时间：
2000-12-01
期刊：
影响因子：
20.3
通讯作者：
Berger, SA
中科院分区：
文献类型：
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作者：
Gommerman, JL;Sittaro, D;Berger, SA
作者研究了PI 3-激酶和PLC-γ在钢因子（SLF）通过c-Kit刺激中的作用，c-Kit突变体YF 719、YF 728和YF 719/F728双突变体在32 D骨髓单核细胞中表达。KitYF 719在用SLF刺激后不能募集PI 3-激酶，而KitYF 728不能刺激PLC-γ磷酸化或动员Ca++。这两个单突变体的有丝分裂响应可溶性SLF（sSLF）的方式与野生型（WT）无法区分，虽然sSLF未能刺激或促进细胞表达的双突变体的生存。相反，尽管表达WT或YF 719的细胞被膜结合的SLF（mSLF）刺激促有丝分裂，但表达KitYF 728的细胞的刺激受损。类似地，表达WT或YF 719受体的细胞被板结合的抗Kit抗体刺激，而表达YF 728受体的细胞不被刺激。PLC拮抗剂硫酸新霉素抑制由sSLF刺激的表达YF 719受体的细胞，新霉素还抑制由mSLF或固定化抗Kit抗体刺激的表达WT受体的细胞，但不抑制sSLF对表达WT或YF 719受体的细胞的刺激，表达KitWT、KitF 719、或KitYF 728注射到小鼠中，并在6至7周后通过集落测定评估细胞的存在。尽管表达KitWT和KitYF 719的细胞均可从脾和骨髓中回收，但KitYF 728细胞从这些器官中的回收率严重降低。这些结果表明，Kit酪氨酸728对于mSLF或固定化配体的促有丝分裂刺激特别重要，并且可能通过PLC-γ的活化而在体内完全维持细胞是必需的。(C)2000年，美国血液学会。
The authors investigated the roles of PI3-kinase and PLC-gamma in stimulation by Steel Factor (SLF) through c-Kit, c-Kit mutants YF719, YF728, and a YF719/F728 double mutant were expressed in 32D myelomonocytic cells. KitYF719 fails to recruit PI3-kinase after stimulation with SLF, whereas KitYF728 fails to stimulate PLC-gamma phosphorylation or mobilize Ca++. Both single mutants responded mitogenically to soluble SLF (sSLF) in a manner indistinguishable from wild type (WT), although sSLF failed to stimulate or promote the survival of cells expressing the double mutant. In contrast, although cells expressing WT or YF719 were mitogenically stimulated by membrane-bound SLF (mSLF), stimulation of cells expressing KitYF728 was impaired, Similarly, cells expressing WT or YF719 receptors were stimulated by plate-bound anti-Kit antibodies, Whereas cells expressing the YF728 receptor were not stimulated. Neomycin sulfate, a PLC antagonist, inhibited cells expressing YF719 receptors stimulated by sSLF, Neomycin also inhibited cells expressing the WT receptor that were stimulated by mSLF or immobilized anti-Kit antibodies but did not inhibit stimulation of cells expressing WT or YF719 receptors by sSLF, 32D cells expressing KitWT, KitF719, or KitYF728 were injected into mice and the presence of cells was evaluated by colony assays 6 to 7 weeks later. Although both KitWT and KitYF719 expressing cells could be recovered from the spleen and bone marrow, recovery of KitYF728 cells from these organs was severely reduced. These results indicate that Kit tyrosine 728 is of particular importance for mitogenic stimulation by mSLF or immobilized ligand and is required for full maintenance of cells in vivo, likely through activation of PLC-gamma. (C) 2000 by The American Society of Hematology.