Novak U, Nice E, Hamilton J A, Paradiso L
University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Australia.
Oncogene. 1996 Dec 19;13(12):2607-13.
Using FDC-P1 derived cell lines which ectopically express either the wild type or mutant forms of the murine CSF-1 receptor in which individual tyrosine residues have been replaced with phenylalanine, we analysed the requirement for tyrosine residues of the receptor for the activation of STAT proteins in response to CSF-1. We found Y706 to be required for efficient activation of STAT1. The activation of STAT3 was not affected by the mutation of Y706 to phenylalanine. The addition of phosphopeptides spanning Y708 of the human CSF-1 receptor (identical with the sequence surrounding Y706 of the murine receptor) to electrophoretic mobility shift assays led to competition of the formation of STAT1 containing complexes, SIF-B and SIF-C with the DNA probe. These phosphopeptides did, however, not affect the formation of the STAT3 containing complex, SIF-A, with the probe. Replacement of Y807 with phenylalanine led to a complete block of activation of all STAT proteins in response to CSF-1, however, this phosphotyrosine does not appear to represent a STAT binding site of the receptor as a phosphopeptide spanning Y809 of the human CSF-1 receptor could not compete any STAT/DNA complex formation in electrophoretic mobility shift assays.
利用异位表达野生型或突变型小鼠CSF-1受体（其中个别酪氨酸残基已被苯丙氨酸取代）的FDC-P1衍生细胞系，我们分析了受体酪氨酸残基对CSF-1刺激下STAT蛋白激活的需求。我们发现Y706是高效激活STAT1所必需的。Y706突变为苯丙氨酸对STAT3的激活没有影响。将跨越人CSF-1受体Y708（与小鼠受体Y706周围序列相同）的磷酸肽添加到电泳迁移率变动分析中，导致含STAT1的复合物SIF-B和SIF-C与DNA探针形成的竞争。然而，这些磷酸肽不影响含STAT3的复合物SIF-A与探针的形成。将Y807替换为苯丙氨酸导致所有STAT蛋白对CSF-1的激活完全受阻，然而，该磷酸酪氨酸似乎并不代表受体的STAT结合位点，因为跨越人CSF-1受体Y809的磷酸肽在电泳迁移率变动分析中不能竞争任何STAT/DNA复合物的形成。
