Solution structure of atypical protein kinase CPB1 domain and its mode of interaction with ZIP/p62 and MEK5
Solution structure of atypical protein kinase CPB1 domain and its mode of interaction with ZIP/p62 and MEK5
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DOI：
10.1074/jbc.m403092200
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发表时间：
2004-07-23
影响因子：
4.8
通讯作者：
Inagaki, F
中科院分区：
文献类型：
--
作者：
Hirano, Y;Yoshinaga, S;Inagaki, F
非典型蛋白激酶C （aPKC）参与多种信号通路，如细胞极性、细胞存活和细胞分化。与其他pkc相比，aPKC在N端具有PB1 （Phox和Bem 1）结构域。aPKC PB1结构域通过PB1-PB1结构域相互作用与ZIP/p62、Par6或MEK5结合，从而控制aPKC的定位。在这里，我们通过NMR确定了PKCiota的PB1结构域的三维结构，发现PB1结构域采用泛素折叠。插入到泛素折叠中的OPCA （OPR， PC和AID）基序呈现为β - α折叠，其中保守的Asp残基侧链定向相同，形成酸性表面。这一结构特征表明PKCiota PB1结构域的酸性表面与目标PB1结构域的碱性表面相互作用，并且通过突变分析在PKCiota- zip /p62配合物的情况下得到了证实。有趣的是，在PKCiota PB1结构域中，一个保守的赖氨酸残基位于OPCA基序呈现表面的对面，这表明PKCiota PB1结构域具有双重作用，它可以与目标PB1结构域的OPCA基序上的保守赖氨酸残基或酸性残基相互作用。
Atypical protein kinase C ( aPKC) has been implicated in several signaling pathways such as cell polarity, cell survival, and cell differentiation. In contrast to other PKCs, aPKC is unique in having the PB1 ( Phox and Bem 1) domain in the N terminus. The aPKC PB1 domain binds with ZIP/p62, Par6, or MEK5 through a PB1-PB1 domain interaction that controls the localization of aPKC. Here, we determined the three-dimensional structure of the PB1 domain of PKCiota by NMR and found that the PB1 domain adopts a ubiquitin fold. The OPCA (OPR, PC, and AID) motif inserted into the ubiquitin fold was presented as a betabetaalpha fold in which the side chains of conserved Asp residues were oriented to the same direction to form an acidic surface. This structural feature suggested that the acidic surface of the PKCiota PB1 domain interacted with the basic surface of the target PB1 domains, and this was confirmed in the case of the PKCiota-ZIP/p62 complex by mutational analysis. Interestingly, in the PKCiota PB1 domain a conserved lysine residue was located on the side opposite to the OPCA motif-presenting surface, suggesting dual roles for the PKCiota PB1 domain in that it could interact with either the conserved lysine residue or the acidic residues on the OPCA motif of the target PB1 domains.