Expression of a novel form of Tec kinase in hematopoietic cells and mapping of the gene to chromosome 5 near Kit.
Expression of a novel form of Tec kinase in hematopoietic cells and mapping of the gene to chromosome 5 near Kit.
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发表时间：
1993-02
期刊：
影响因子：
8
通讯作者：
H. Mano;Kozue Mano;Bo Tang;Maria Koehler;T. Yi;D. J. Gilbert;Nancy A. Jenkins;N. G. Copeland;James N. Ihle
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作者：
H. Mano;Kozue Mano;Bo Tang;Maria Koehler;T. Yi;D. J. Gilbert;Nancy A. Jenkins;N. G. Copeland;James N. Ihle
Tec激酶最初被鉴定为一种新的细胞质蛋白酪氨酸激酶，它在肝脏中优先表达，与果蝇Dsrc28C src相关的酪氨酸激酶高度同源。在对白介素3(IL-3)依赖的髓系白血病细胞进行蛋白酪氨酸激酶的筛选中，我们观察到所有细胞株都表达高水平的Tec转录本。然而，Tec cDNA的特征表明它们与已发表的序列有很大的不同。最引人注目的是，在5‘端插入41bp会影响起始密码子，并导致已发表的13个氨基酸的氨基末端序列被94个氨基酸取代。用聚合酶链式反应(PCR)分析，在造血细胞中只检测到含有插入片段的形式。此外，我们还发现了一个66bp的框内插入，它在SH3结构域中引入了另外22个氨基酸。该插入恢复了在src基因家族和Dsrc28C基因中发现的保守的SH3序列。经PCR分析，在造血细胞中发现含有完整SH3结构域和含有22个氨基酸缺失的Tec转录本的水平大致相同。最后，通过种间回交分析，我们发现Tec基因与小鼠5号染色体上的c-Kit基因紧密连锁。
The Tec kinase was initially identified as a novel cytoplasmic protein tyrosine kinase that is preferentially expressed in the liver and is highly homologous to the Drosophila Dsrc28C src-related tyrosine kinase. In screening of interleukin 3 (IL-3)-dependent myeloid leukemia cells for protein tyrosine kinases, we observed that all cell lines examined expressed high levels of Tec transcripts. However, characterization of Tec cDNAs indicated that they differed significantly from the published sequence. Most strikingly, an insertion of 41 bp in the 5' region affects the initiation codon and results in replacing the published 13 amino acid amino-terminal sequences with 94 amino acids. Using polymerase chain reaction (PCR) analysis, only the form containing the insertion was detected in hematopoietic cells. In addition, we found an in-frame insertion of 66 bp that introduces an additional 22 amino acids into the SH3 domain. This insertion restores conserved SH3 sequences that are found in the src gene family and in the Dsrc28C gene. By PCR analysis, approximately equal levels of Tec transcripts containing the intact SH3 domain and containing the 22 amino acid deletion were found in hematopoietic cells. Lastly, by interspecies backcross analysis, we show that the Tec gene is tightly linked to the c-Kit gene on mouse chromosome 5.