Huang D Y, Prystowsky M B
Graduate group of Molecular Biology, University of Pennsylvania, School of Medicine, Philadelphia 19104, USA.
J Biol Chem. 1996 Jan 12;271(2):1218-25. doi: 10.1074/jbc.271.2.1218.
Interleukin 2 (IL-2) stimulates T lymphocyte proliferation and induces the expression of proliferating cell nuclear antigen (PCNA), a processivity factor for DNA polymerase delta. Previously, deletion analysis suggested cis-element(s) in the proximal region of the PCNA promoter (-40 to +143) are required for IL-2 induction in cloned T lymphocytes. The sequence 5'-TTGCGGGC-3' located at +10 to +17 is similar to the E2F consensus binding site and is required for optimal PCNA promoter activity. In IL-2-stimulated T cells, nuclear proteins are induced to bind to this sequence as demonstrated using electrophoretic mobility shift assay (EMSA), competition EMSA, and methylation interference analysis. A 180-kDa polypeptide was detected by UV cross-linking to bind specifically to the PCNA E2F-like sequence. Our data indicate that the protein bound to the PCNA E2F-like site is not one of the transcription factor E2F proteins. Our results demonstrate that the E2F-like sequence and the protein(s) binding to it are required for optimal PCNA promoter activity and IL-2 induction of PCNA expression.
白细胞介素2（IL-2）刺激T淋巴细胞增殖并诱导增殖细胞核抗原（PCNA）的表达，PCNA是DNA聚合酶δ的持续合成因子。此前，缺失分析表明，在克隆的T淋巴细胞中，IL-2诱导需要PCNA启动子近端区域（-40至+143）中的顺式元件。位于+10至+17的序列5'-TTGCGGGC-3'与E2F共有结合位点相似，是PCNA启动子最佳活性所必需的。在IL-2刺激的T细胞中，如使用电泳迁移率变动分析（EMSA）、竞争EMSA和甲基化干扰分析所证明的，核蛋白被诱导结合到该序列。通过紫外线交联检测到一种180 kDa的多肽特异性结合到PCNA E2F样序列。我们的数据表明，结合到PCNA E2F样位点的蛋白质不是转录因子E2F蛋白之一。我们的结果表明，E2F样序列及其结合蛋白是PCNA启动子最佳活性和IL-2诱导PCNA表达所必需的。
