Renjifo B, Speck N A, Winandy S, Hopkins N, Li Y
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139.
J Virol. 1990 Jun;64(6):3130-4. doi: 10.1128/JVI.64.6.3130-3134.1990.
A series of 5' deletions and a point mutation in the binding site for nuclear factor kappa B were introduced into the U3 region of a molecular clone of simian immunodeficiency virus from macaques (SIVmac142). The transcriptional activity of the mutated U3 regions was analyzed by transient chloramphenicol acetyltransferase assays. Two distinct regions in U3 appeared to contain important cis-acting sequences for transcriptional activity. Mutation of the single nuclear factor kappa B site in the SIVmac142 U3 region attenuated transcription in Rat-1 fibroblasts and Jurkat T cells. A second cis-acting element was localized to sequences between -162 and -114 in U3; deletion of long terminal repeat sequences up to -114 significantly attenuated transcriptional activity in Rat-1 cells. Furthermore, sequences between -162 and -114 contributed to inducibility of transcription by 1,3-phorbol myristate acetate in Jurkat T cells. Deletion of long terminal repeat sequences to -114, in addition to mutation of the nuclear factor kappa B site, was necessary to attenuate the response to 1,3-phorbol myristate acetate completely. A negative regulatory element analogous to that identified in the U3 region from the human immunodeficiency virus was not found in the U3 region from SIVmac142.
将一系列5'缺失和一个位于核因子κB结合位点的点突变引入猕猴猿猴免疫缺陷病毒（SIVmac142）分子克隆的U3区域。通过瞬时氯霉素乙酰转移酶分析来检测突变U3区域的转录活性。U3中有两个不同区域似乎包含转录活性所需的重要顺式作用序列。SIVmac142 U3区域中单个核因子κB位点的突变会减弱大鼠-1成纤维细胞和Jurkat T细胞中的转录。第二个顺式作用元件定位于U3中-162至-114之间的序列；缺失至-114的长末端重复序列会显著减弱大鼠-1细胞中的转录活性。此外，-162至-114之间的序列有助于Jurkat T细胞中佛波酯诱导的转录。除了核因子κB位点的突变外，将长末端重复序列缺失至-114对于完全减弱对佛波酯的反应是必要的。在SIVmac142的U3区域未发现类似于在人类免疫缺陷病毒U3区域中鉴定出的负调控元件。
