信号转导子与转录激活子(Signal transducerand activator of transcription,STAT)广泛参与细胞因子的信号转导,从而对细胞增生、分化和存活等进行调节。在生理条件下,细胞因子与靶细胞膜上的受体结合后,受体发生二聚化,进而激活受体相关性激酶JAKs。受体上的特异位点的酪氨酸残基被JAKs磷酸化后,为胞质中的STATs提供结合位点。STATs被JAK磷酸化而激活,形成同源或异源二聚体,转运至细胞核,与靶基因的启动子 Signal transducers and activators of transcription (Signal transducers and activators of transcription) are widely involved in signal transduction of cytokines to regulate cell proliferation, differentiation and survival. Under physiological conditions, the binding of cytokines to receptors on the target cell membrane causes dimerization of the receptor, which in turn activates the receptor-associated kinase JAKs. Tyrosine residues at specific sites on the receptor, phosphorylated by JAKs, provide binding sites for STATs in the cytoplasm. STATs are phosphorylated and activated by JAK to form homodimers or heterodimers, which are transported to the nucleus to interact with the promoter of the target gene