Lu X, Li Y
Department of Molecular Biosciences, The University of Kansas, Lawrence, Kansas 66045, USA.
Dev Biol. 1999 Apr 1;208(1):233-43. doi: 10.1006/dbio.1999.9196.
The Src family of nonreceptor tyrosine kinases has been implicated in many signal transduction pathways. However, due to a possible functional redundancy in vertebrates, there is no genetic loss-of-function evidence that any individual Src family member has a crucial role for receptor tyrosine kinase (RTK) signaling. Here we show that an extragenic suppressor of Raf, Su(Raf)1, encodes a Drosophila Src family gene Src42A. Characterization of Src42A mutations shows that Src42A acts independent of Ras1 and that it is, unexpectedly, a negative regulator of RTK signaling. Our study provides the first evidence that Src42A defines a negative regulatory pathway parallel to Ras1 in the RTK signaling cascade. A possible model for Src42A function is discussed.
非受体酪氨酸激酶的Src家族与许多信号转导途径有关。然而，由于脊椎动物中可能存在功能冗余，尚无基因功能丧失的证据表明任何单个Src家族成员对受体酪氨酸激酶（RTK）信号传导具有关键作用。在此，我们表明Raf的一个基因外抑制因子Su（Raf）1编码一种果蝇Src家族基因Src42A。对Src42A突变的表征表明，Src42A的作用独立于Ras1，并且出乎意料的是，它是RTK信号传导的负调节因子。我们的研究提供了首个证据，表明Src42A在RTK信号级联反应中定义了一条与Ras1平行的负调节途径。文中讨论了Src42A功能的一种可能模型。
