The LxVP and PxIxIT NFAT Motifs Bind Jointly to Overlapping Epitopes on Calcineurin's Catalytic Domain Distant to the Regulatory Domain
The LxVP and PxIxIT NFAT Motifs Bind Jointly to Overlapping Epitopes on Calcineurin's Catalytic Domain Distant to the Regulatory Domain
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DOI：
10.1016/j.str.2014.05.006
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发表时间：
2014-07-08
期刊：
影响因子：
5.7
通讯作者：
Wagner, Gerhard
中科院分区：
文献类型：
--
作者：
Gal, Maayan;Li, Shuai;Wagner, Gerhard
丝氨酸/苏氨酸磷酸酶钙调神经磷酸酶(CN)以激活细胞因子基因的活化T细胞(NFATs)的核因子为靶标。钙内流激活CN去磷酸化与200个氨基酸残基相似的NFAT调控区域内的多个丝氨酸残基，从而触发NFAT和CN的联合核转位。去磷酸化过程依赖于CN与保守基序PxIxIT和LxVP之间的相互作用，PxIxIT和LxVP位于NFAT调节结构域的磷酸化位点的N端和C端。在这里，我们发现一个由NFATc1衍生的包含保守的LxVP基序的15个残基的多肽片段与CN的催化结构域(CNA)上的一个表位结合，该表位与先前在CNA上建立的PxIxIT结合位点重叠，并远离调节域(CNB)。这两个NFAT基序在CNA表位上部分竞争结合，但并不完全置换，表明两个片段同时与催化结构域上的同一表位结合。
The serine/threonine phosphatase calcineurin (Cn) targets the nuclear factors of activated T cells (NFATs) that activate cytokine genes. Calcium influx activates Cn to dephosphorylate multiple serine residues within the similar to 200 residue NFAT regulatory domain, which triggers joint nuclear translocation of NFAT and Cn. The dephosphorylation process relies on the interaction between Cn and the conserved motifs PxIxIT and LxVP, which are located N- and C-terminal to the phosphorylation sites in NFAT's regulatory domain. Here, we show that an NFATc1-derived 15-residue peptide segment containing the conserved LxVP motif binds to an epitope on Cn's catalytic domain (CnA), which overlaps with the previously established PxIxIT binding site on CnA and is distant to the regulatory domain (CnB). Both NFAT motifs partially compete for binding but do not fully displace each other on the CnA epitope, revealing that both segments bind simultaneously to the same epitope on the catalytic domain.