Identification and characterization of PKNβ, a novel isoform of protein kinase PKN:: Expression and arachidonic acid dependency are different from those of PKNα
Identification and characterization of PKNβ, a novel isoform of protein kinase PKN:: Expression and arachidonic acid dependency are different from those of PKNα
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DOI：
10.1006/bbrc.1999.1116
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发表时间：
1999-08-11
影响因子：
3.1
通讯作者：
Ona, Y
中科院分区：
文献类型：
--
作者：
Oishi, K;Mukai, H;Ona, Y
从 HeLa cDNA 文库中分离出编码蛋白激酶 PKN 新型亚型（称为 PKN beta）的 cDNA 克隆。 PKN beta 与 PKN α（最初分离的 PKN）具有高度序列同源性，特别是在羧基末端催化结构域中具有亮氨酸拉链样序列的带电氨基酸丰富区（CZ 区/HR1）的重复中，以及位于 CZ 区/HR1 和催化结构域之间的类似于 130 个氨基酸的延伸区（D 区/HR2）。然而，PKN β 的氨基酸序列与 PKN α 的氨基酸序列在紧邻催化结构域氨基末端的区域不同，该区域包含两个不同的富含脯氨酸的序列，与 II 类共有序列 PXXPXR 一致，用于与 SH3 结构域结合。 PKN β的分布与PKN α的分布有以下两个方面的不同：（1）Northern印迹表明，在人类成人组织中无法检测到PKN β mRNA，但在人类癌细胞系中大量表达； (2)免疫化学分析表明，NIH3T3细胞中PKNβ定位于细胞核和核周凝胶器，胞质区几乎不存在。在 COS7 细胞中表达的重组 PKN β 显示出自磷酸化和肽激酶活性，但发现对花生四烯酸的反应明显低于 PKN α。这种新型亚型的鉴定强调了 PKN 信号通路的多样性。 (C) 1999 年学术出版社。
The cDNA clone encoding a novel isoform of protein kinase PKN, termed PKN beta, was isolated from a HeLa cDNA library. PKN beta had high sequence homology with PKN alpha, originally isolated PKN, especially in the repeats of charged amino acid-rich region with leucine-zipper like sequences (CZ region/HR1), in the carboxyl-terminal catalytic domain, and in similar to 130 amino acid stretch (D region/HR2), located between CZ region/HR1 and the catalytic domain. However, the amino acid sequence of PKN beta differed from that of PKN alpha in the region immediately amino-terminal to the catalytic domain, which contained two distinct proline-rich sequences consistent with the class II consensus sequence, PXXPXR, for binding to SH3 domain. Distribution of PKN beta differed from that of PKN alpha in the following two respects: (1) Northern blotting indicated that PKN beta mRNA could not be detected in human adult tissues, but was expressed abundantly in human cancer cell lines; (2) immunochemical analysis indicated that PKN beta localized in nucleus and perinuclear Gels apparatus, and was almost absent in cytoplasmic region in NIH3T3 cells. Recombinant PKN beta expressed in COS7 cells displayed autophosphorylation and peptide kinase activity, but was found to be significantly less responsive to arachidonic acid than PKN alpha. The identification of this novel isoform underscores the diversity of PKN signaling pathway. (C) 1999 Academic Press.