Functional analysis of the long terminal repeats of intracisternal A-particle genes: Sequences within the U3 region determine both the efficiency and direction of promoter activity

Journal Article · Tue Mar 01 04:00:00 EST 1988 · Mol. Cell. Biol.; (United States)

DOI:https://doi.org/10.1128/MCB.8.3.1093· OSTI ID:7155530

Christy, R J; Huang, R C.C.

The transcriptional activity of five intracisternal A-particle (IAP) long terminal repeats (LTRs) in mouse embryonal carcinoma PCC3-A/1 cells and in Ltk/sup -/ cells was determined. The authors tested the promoter activity of the LTRs by coupling them to the reporter gene chloramphenicol acetyltransferase (CAT) or guanosine-xanthine phosphoribosyltransferase (gpt). Each LTR was tested for promoter function in both the sense (5' to 3') and antisense (3' to 5') orientation preceding the reporter gene. The transcriptional activity of individual IAP gene LTRs varied considerably, and the LTR from IAP81 possessed promoter activity in both directions. The bidirectional activity of the IAP81 LTR was confirmed by monitoring Ecogpt expression in stably transfected Ltk/sup -/ cells, with the initiation sites for sense and antisense transcription being localized to within the IAP81 LTR by S1 nuclease mapping. Deletions of LTR81 show that for normal 5'-to-3' gene transcription (sense direction), the /sup 3'/U3/R region determines the basal level of transcription, whereas sequences within the /sup 5'/U3 region enhance transcription four- to fivefold. Deletion mapping for antisense transcription indicates that a 64-base-pair region (nucleotides 47 to 110) within the U3 region is essential for activity. These data indicate that the U3 region contains all the regulatory elements for bidirectional transcription in IAP LTRs.

• Research Organization: Dept. of Biological Chemistry, The Johns Hopkins School of Medicine, Baltimore, MD (US)
• OSTI ID: 7155530
• Journal Information: Mol. Cell. Biol.; (United States), Journal Name: Mol. Cell. Biol.; (United States) Vol. 8:3; ISSN MCEBD
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
BIOLOGICAL FUNCTIONS
CHLORAMPHENICOL
CHROMOSOME LOSSES
DNA-ASE
DRUGS
EMBRYONIC CELLS
ENDONUCLEASES
ENZYME ACTIVITY
ENZYMES
ESTERASES
FUNCTIONS
GENE OPERONS
GENE REGULATION
GENES
GENETIC MAPPING
HYDROLASES
LOSSES
MAMMALS
MAPPING
MICE
NUCLEOPROTEINS
ORGANIC COMPOUNDS
PHENOTYPE
PHOSPHODIESTERASES
PROTEINS
RODENTS
TRANSCRIPTION
TRANSFERASES
TUMOR CELLS
VERTEBRATES