Activation of hematopoietic progenitor kinase 1 involves relocation, autophosphorylation, and transphosphorylation by protein kinase D1
Activation of hematopoietic progenitor kinase 1 involves relocation, autophosphorylation, and transphosphorylation by protein kinase D1
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DOI：
10.1128/mcb.25.6.2364-2383.2005
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发表时间：
2005-03-01
影响因子：
5.3
通讯作者：
Kiefer, F
中科院分区：
文献类型：
--
作者：
Arnold, R;Patzak, IM;Kiefer, F
适应性免疫信号可以耦合到应激激活蛋白激酶(SAPK)/c-jun n -末端激酶（JNK）和NF-kappaB被造血祖激酶1 （HPK1）激活，HPK1是一种哺乳动物造血特异性Ste20激酶。为了深入了解白细胞信号转导的调控，我们研究了HPK1激活的分子细节。在这里，我们证明了Src家族激酶Lck和SLP-76家族接头蛋白Clnk（细胞因子依赖性造血细胞连接物）诱导HPK1酪氨酸磷酸化并重新定位到质膜的能力，这在淋巴细胞中导致HPK1募集到抗原呈递细胞(APC)- t细胞偶联物的接触部位。HPK1的重新定位和聚集导致其酶激活，这伴随着HPK1激酶激活环中调控位点的磷酸化。我们发现HPK1的完全激活依赖于苏氨酸165的自磷酸化和丝氨酸171的磷酸化，而丝氨酸171是体外蛋白激酶D （PKD）的靶点。在T细胞受体刺激下，PKD显著增强Jurkat T细胞中HPK1激酶活性，并增强HPK1驱动的SAPK/JNK和NF-kappaB激活；相反，PKD的反义下调导致HPK1活性降低。因此，通过HPK1激活主要淋巴细胞信号通路涉及PKD对HPK1的(i)重新定位，(h)自磷酸化和（iii）转磷酸化。
Adaptive immune signaling can be coupled to stress-activated protein kinase (SAPK)/c-jun N-terminal kinase (JNK) and NF-kappaB activation by the hematopoietic progenitor kinase 1 (HPK1), a mammalian hematopoiesis-specific Ste20 kinase. To gain insight into the regulation of leukocyte signal transduction, we investigated the molecular details of HPK1 activation. Here we demonstrate the capacity of the Src family kinase Lck and the SLP-76 family adaptor protein Clnk (cytokine-dependent hematopoietic cell linker) to induce HPK1 tyrosine phosphorylation and relocation to the plasma membrane, which in lymphocytes results in recruitment of HPK1 to the contact site of antigen-presenting cell (APC)-T-cell conjugates. Relocation and clustering of HPK1 cause its enzymatic activation, which is accompanied by phosphorylation of regulatory sites in the HPK1 kinase activation loop. We show that full activation of HPK1 is dependent on autophosphorylation of threonine 165 and phosphorylation of serine 171, which is a target site for protein kinase D (PKD) in vitro. Upon T-cell receptor stimulation, PKD robustly augments HPK1 kinase activity in Jurkat T cells and enhances HPK1-driven SAPK/JNK and NF-kappaB activation; conversely, antisense down-regulation of PKD results in reduced HPK1 activity. Thus, activation of major lymphocyte signaling pathways via HPK1 involves (i) relocation, (h) autophosphorylation, and (iii) transphosphorylation of HPK1 by PKD.