An active kinase domain is required for retention of PKCθ at the T cell immunological synapse.
An active kinase domain is required for retention of PKCθ at the T cell immunological synapse.
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DOI：
10.1091/mbc.e10-11-0916
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发表时间：
2011-09
影响因子：
3.3
通讯作者：
Schaefer BC
中科院分区：
文献类型：
--
作者：
Cartwright NG;Kashyap AK;Schaefer BC
在抗原刺激下，PKCθ易位到T细胞膜，高度聚焦于免疫突触（IS）。调节IS保留的顺式作用序列尚不清楚。研究表明，具有催化能力的PKCθ激酶结构域对is保留是必需的，但对膜易位不是必需的。蛋白激酶Cθ (PKCθ)是一种丝氨酸/苏氨酸激酶，在T淋巴细胞抗原调节反应中起重要作用。在抗原刺激下，PKCθ被迅速募集到免疫突触（is），这是T细胞和抗原呈递细胞之间的接触区域。这种行为在T细胞PKC亚型中是独特的。为了确定在IS中保留PKCθ所需的结构域，我们生成了PKCθ的缺失突变体和点突变体。我们使用定量成像分析来评估抗原刺激T细胞克隆中PKCθ突变体的IS保留。激酶结构域的缺失或已知PKCθ磷酸化位点子集的位点定向突变分别废除或显着降低IS保留。IS的保留与特定PKCθ残基的磷酸化无关，而与激酶功能有关。因此PKCθ的催化能力对于is的稳定保留至关重要。
In response to antigen stimulation, PKCθ translocates to the T cell plasma membrane, becoming highly focused at the immunological synapse (IS). cis-Acting sequences that regulate IS retention are not known. It is shown that a catalytically competent PKCθ kinase domain is essential for IS retention but not for membrane translocation. Protein kinase Cθ (PKCθ) is a serine/threonine kinase that plays an essential role in antigen-regulated responses of T lymphocytes. Upon antigen stimulation, PKCθ is rapidly recruited to the immunological synapse (IS), the region of contact between the T cell and antigen-presenting cell. This behavior is unique among T cell PKC isoforms. To define domains of PKCθ required for retention at the IS, we generated deletion and point mutants of PKCθ. We used quantitative imaging analysis to assess IS retention of PKCθ mutants in antigen-stimulated T cell clones. Deletion of the kinase domain or site-directed mutation of a subset of known PKCθ phosphorylation sites abrogated or significantly reduced IS retention, respectively. IS retention did not correlate with phosphorylation of specific PKCθ residues but rather with kinase function. Thus PKCθ catalytic competence is essential for stable IS retention.