Schröter H, Mueller C G, Meese K, Nordheim A
Zentrum für Molekulare Biologie (ZMBH), Universität Heidelberg, FRG.
EMBO J. 1990 Apr;9(4):1123-30. doi: 10.1002/j.1460-2075.1990.tb08218.x.
Transcriptional regulation of the c-fos proto-oncogene requires the serum response element (SRE) which is complexed by a multi-protein assembly observed both in vitro and in vivo. Two protein factors, p67SRF and p62TCF (previously called p62), are required to interact with the SRE for efficient induction of c-fos by serum. By quantitative band shift electrophoresis we measure at least a 50-fold increase in SRE affinity for p67SRF/p62TCF over p67SRF alone. Stoichiometrically we determine that the ternary complex with p62TCF involves p67SRF in dimeric form. We demonstrate that p67SRF is a glycosylated nuclear transcription factor carrying terminal N-acetylglucosamine (GlcNAc) as a post-translational modification. A proteolytic limit digestion product, approximately 13 kd in size, was generated from the p67SRF-SRE complex. This p67SRF-core domain binds SRE, can dimerize with p67SRF and is still able to form a ternary complex with p62TCF. Therefore, three functional activities can be ascribed to this small p67SRF-core domain: specific DNA binding, dimerization and interaction with p62TCF. We demonstrate that these functions map within the p67SRF core fragment containing the region between amino acids 93 and 222.
原癌基因c-fos的转录调控需要血清反应元件（SRE），它在体外和体内都与一种多蛋白复合体相结合。血清高效诱导c-fos需要两种蛋白因子，即p67SRF和p62TCF（以前称为p62）与SRE相互作用。通过定量凝胶迁移电泳，我们测量出SRE对p67SRF/p62TCF的亲和力比对单独的p67SRF至少高50倍。从化学计量学角度我们确定，与p62TCF形成的三元复合体中，p67SRF是以二聚体形式存在。我们证明p67SRF是一种糖基化的核转录因子，其末端N-乙酰葡糖胺（GlcNAc）作为翻译后修饰。从p67SRF-SRE复合体产生了一种大小约为13kd的蛋白水解极限消化产物。这个p67SRF核心结构域能结合SRE，可与p67SRF二聚化，并且仍然能够与p62TCF形成三元复合体。因此，这种小的p67SRF核心结构域具有三种功能活性：特异性DNA结合、二聚化以及与p62TCF相互作用。我们证明这些功能定位在包含氨基酸93至222之间区域的p67SRF核心片段内。
