Cheng J T, Hsu H L, Hwang L Y, Baer R
Department of Microbiology, University of Texas, Dallas 75235.
Oncogene. 1993 Mar;8(3):677-83.
TAL1 gene rearrangement is observed in nearly 30% of patients with T-cell acute lymphoblastic leukemia (T-ALL), and thus it represents the most common genetic lesion associated with this disease. Nevertheless, the presence of TAL1 gene products in normal or leukemic cells has not been reported. Therefore, immunoprecipitation with anti-TAL1 antisera was used to demonstrate the presence of TAL1 phosphoproteins, pp42TAL1 and pp22TAL1, in both T-ALL and erythroleukemia cell lines. The pp42TAL1 and pp22TAL1 proteins appear to be phosphorylated forms of full-length and truncated TAL1 gene products respectively. Phosphoamino acid analysis revealed that pp42TAL1 contains phosphoserine residues. The TAL1 phosphoproteins were detected in all of the T-ALL cell lines that harbor obvious TAL1 gene rearrangements. Interestingly, pp42TAL1 and pp22TAL1 were also present in some, but not all, of the T-ALL lines without detectable TAL1 gene alterations. Therefore, TAL1 activation may promote leukemogenesis in a far greater proportion of T-ALL patients than the 30% that bear gross TAL1 gene rearrangements.
在近30%的T细胞急性淋巴细胞白血病（T-ALL）患者中观察到TAL1基因重排，因此它是与该疾病相关的最常见的基因损伤。然而，尚未有关于正常或白血病细胞中TAL1基因产物存在情况的报道。因此，使用抗TAL1抗血清进行免疫沉淀，以证明TAL1磷酸化蛋白pp42TAL1和pp22TAL1在T-ALL和红白血病细胞系中的存在。pp42TAL1和pp22TAL1蛋白似乎分别是全长和截短的TAL1基因产物的磷酸化形式。磷酸氨基酸分析表明pp42TAL1含有磷酸丝氨酸残基。在所有具有明显TAL1基因重排的T-ALL细胞系中都检测到了TAL1磷酸化蛋白。有趣的是，在一些（但不是全部）未检测到TAL1基因改变的T-ALL细胞系中也存在pp42TAL1和pp22TAL1。因此，与30%发生明显TAL1基因重排的T-ALL患者相比，TAL1激活可能在更大比例的T-ALL患者中促进白血病发生。
