title: Multiple sequence elements are required for regulation of human T-cell leukemia virus gene expression.
abstract: The U3 region of the long terminal repeat (LTR) of human T-cell leukemia virus type I (HTLV-I) contains sequences that respond to the trans-activating transcription (tat) factor encoded by the pX region of the provirus. Results presented here show that there are multiple tat-responsive sequences within the LTR and that a single 21-nucleotide sequence, which is repeated three times within the U3 region, is sufficient to determine the response to the trans-activator. This sequence is capable of conferring a tat-responsive phenotype upon the HTLV-I and simian virus 40 promoters, independent of orientation. Sequences required for efficient HTLV-I LTR-directed gene expression are also located 3' to the site of RNA initiation, within the R and U5 regions of the LTR.
mesh_terms: D001483:Base Sequence; D017977:Deltaretrovirus / Q000235:genetics*; D005786:Gene Expression Regulation; D015696:Gene Products, tat; D005814:Genes, Viral; D009856:Oncogene Proteins, Viral / Q000502:physiology*; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D015696:Gene Products, tat; D009856:Oncogene Proteins, Viral; D014157:Transcription Factors