A KINASE-NEGATIVE EPIDERMAL GROWTH-FACTOR RECEPTOR THAT RETAINS THE CAPACITY TO STIMULATE DNA-SYNTHESIS
A KINASE-NEGATIVE EPIDERMAL GROWTH-FACTOR RECEPTOR THAT RETAINS THE CAPACITY TO STIMULATE DNA-SYNTHESIS
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DOI：
10.1073/pnas.91.15.6967
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发表时间：
1994-07-19
影响因子：
11.1
通讯作者：
GUYER, CA
中科院分区：
文献类型：
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作者：
COKER, KJ;STAROS, JV;GUYER, CA
将人表皮生长因子受体（EGFR）的磷酰基转移催化碱基Asp-813突变为Ala，并在中国仓鼠卵巢（CHO）细胞中表达突变受体（D813 A）。部分纯化的D813 A在不存在或存在EGF的情况下均未表现出可检测的激酶活性。在完整细胞中可检测到低水平的EGF刺激的D813 A磷酸化，这显然是由于相关Tyr激酶的活性。如先前观察到的激酶失活的Lys-721突变体，EGF结合到D813 A刺激促分裂原活化蛋白激酶活性。令人惊讶的是，与报道的Lys-721突变体的结果不同，D813 A能够刺激Rb-86（+）摄取和DNA合成以响应EGF。这些数据不仅表明Asp-813对EGFR的催化活性至关重要，而且还表明激酶阴性Lys-721和激酶阴性Asp-813 EGFR突变体的信号传导特性可能存在差异。
The residue proposed to serve as the catalytic base for phosphoryl transfer, Asp-813, of the human epidermal growth factor receptor (EGFR) was mutated to Ala, and the mutant receptor (D813A) was expressed in Chinese hamster ovary (CHO) cells. Partially purified D813A exhibited no detectable kinase activity in the absence or presence of EGF. A low level of EGF-stimulable phosphorylation of D813A was detectable in intact cells, apparently due to the activity of an associated Tyr kinase(s). As previously observed for kinase-inactive Lys-721 mutants, EGF binding to D813A stimulates mitogen-activated protein kinase activity. Surprisingly, and unlike results reported for Lys-721 mutants, D813A is capable of stimulating both Rb-86(+) uptake and DNA synthesis in response to EGF. These data suggest not only that Asp-813 is critical to the catalytic activity of the EGFR but also that differences may exist in the signaling properties of kinase-negative Lys-721 and kinase-negative Asp-813 EGFR mutants.