de Castro Rodrigo Orlandini
Receptors and Signal Transduction Section, Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.
J Signal Transduct. 2011;2011:507291. doi: 10.1155/2011/507291. Epub 2011 May 12.
The protein tyrosine kinase Syk plays a critical role in FcεRI signaling in mast cells. Binding of Syk to phosphorylated immunoreceptor tyrosine-based activation motifs (p-ITAM) of the receptor subunits results in conformational changes and tyrosine phosphorylation at multiple sites that leads to activation of Syk. The phosphorylated tyrosines throughout the molecule play an important role in the regulation of Syk-mediated signaling. Reconstitution of receptor-mediated signaling in Syk(-/-) cells by wild-type Syk or mutants which have substitution of these tyrosines with phenylalanine together with in vitro assays has been useful strategies to understand the regulation and function of Syk.
蛋白酪氨酸激酶Syk在肥大细胞的FcεRI信号传导中起关键作用。Syk与受体亚基的磷酸化基于免疫受体酪氨酸的激活基序（p-ITAM）结合，导致构象变化和多个位点的酪氨酸磷酸化，进而激活Syk。整个分子中的磷酸化酪氨酸在Syk介导的信号调节中起重要作用。通过野生型Syk或用苯丙氨酸替代这些酪氨酸的突变体在Syk（-/-）细胞中重建受体介导的信号传导，并结合体外实验，是理解Syk的调节和功能的有用策略。
