Heim M H, Kerr I M, Stark G R, Darnell J E
Laboratory of Molecular Cell Biology, Rockefeller University, New York, NY 10021.
Science. 1995 Mar 3;267(5202):1347-9. doi: 10.1126/science.7871432.
In response to specific ligands, various STAT proteins (signal transducers and activators of transcription) are phosphorylated on tyrosine by Jak protein kinases and translocated to the nucleus to direct gene transcription. Selection of a STAT at the interferon gamma receptor as well as specific STAT dimer formation depended on the presence of particular SH2 groups (phosphotyrosine-binding domains), whereas the amino acid sequence surrounding the phosphorylated tyrosine on the STAT could vary. Thus, SH2 groups in STAT proteins may play crucial roles in specificity at the receptor kinase complex and in subsequent dimerization, whereas the kinases are relatively nonspecific.
响应特定配体时，各种信号转导子和转录激活子（STAT）蛋白会被Jak蛋白激酶磷酸化酪氨酸，并转移至细胞核以指导基因转录。干扰素γ受体处对STAT的选择以及特定的STAT二聚体形成取决于特定SH2结构域（磷酸酪氨酸结合结构域）的存在，而STAT上磷酸化酪氨酸周围的氨基酸序列可能有所不同。因此，STAT蛋白中的SH2结构域可能在受体激酶复合物的特异性以及随后的二聚化过程中发挥关键作用，而激酶相对缺乏特异性。
