Identification of a cis-acting element in the class I major histocompatibility complex gene promoter responsive to activation by retroviral sequences
| Autor: | Sang Yun Choi, Douglas V. Faller, K van de Mark |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Transcriptional Activation
Immunology Response element Microbiology Mice Transactivation Virology MHC class I Animals Humans Electrophoretic mobility shift assay Promoter Regions Genetic Repetitive Sequences Nucleic Acid Regulation of gene expression biology Histocompatibility Antigens Class I MHC Class I Gene Promoter 3T3 Cells Molecular biology Long terminal repeat Tumor Virus Infections Insect Science biology.protein Moloney murine leukemia virus Retroviridae Infections Research Article |
| Zdroj: | Journal of Virology. 71:965-970 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.71.2.965-970.1997 |
| Popis: | The infection of cells with Moloney murine leukemia virus (M-MuLV) causes an increase in specific cellular gene products, including the major histocompatibility complex (MHC) class I antigens. This upregulation occurs through a transactivation process mediated by the long terminal repeat (LTR) of M-MuLV, and we show here that the gene activation response to the LTR requires at least one specific cis element within the MHC proximal promoter region. Nested deletions of MHC class I H-2Kb gene promoter sequence were subcloned into a chloramphenicol acetyltransferase (CAT) reporter vector and then transiently introduced into BALB/c-3T3 cells expressing M-MuLV or cotransfected into BALB/c-3T3 cells with a vector containing subgenomic portions of the virus, including the LTR. CAT activity assays demonstrated that a minimal H-2Kb gene promoter (-64 to +12) contained elements sufficient for this transactivation. DNase I footprinting assays located a protein-binding site in the region of -64 to -34 bp from the transcriptional start site, and point mutation analysis confirmed the location of this cis-acting element, designated the let response element (LRE), and defined a binding motif. This LRE is distinct from binding sites for currently known transcription factors in the class I MHC gene promoter and is conserved in the promoters of human and murine MHC class I genes. Mutation of the LRE resulted in dramatic reduction in both DNA-protein binding activity in electrophoretic mobility shift assay and in the ability of the mutated promoter to respond to retroviral transactivation. Addition of the LRE to a heterologous promoter conferred the ability to respond to retroviral transactivation. |
| Databáze: | OpenAIRE |
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