Demonstration of a divergent transcript from the bidirectional heavy chain immunoglobulin promoter VH441 in B-cells.
The mouse heavy chain immunoglobulin promoter VH441 can lead in vitro to bidirectional transcription, due to a symmetrical organization of immunoglobulin heavy chain promoters with two TATA-like sequences bracketing the upstream promoter element ATGCAAAT (the so called octamer). We demonstrate here that divergent transcription also occurs in vivo in mature B cells from a myeloma which expresses the VH441 gene and even from the spleen of BALB/c mice. The level of VH441 divergent transcript increases in the spleen of BALB/c mice after immunisation by beta-(1,6)-galactan, showing that it is expressed in B cells which actively transcribe the VH441 gene. The divergent transcript has been characterized: its major transcription start site was mapped within 33 base pairs from the divergent TATA-like region, it is unspliced and not polyadenylated. In the light of these results, the functions of the divergent transcript and the bidirectional promoter are discussed.
Nguyen
Q T
QT
Institut Pasteur, URA CNRS 361, Département d'Immunologie, Paris, France.
Doyen
N
N
d'Andon
M F
MF
Rougeon
F
F
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D001483:Base Sequence; D015152:Blotting, Northern; D005685:Galactans / Q000494:pharmacology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009101:Multiple Myeloma / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013154:Spleen / Q000378:metabolism; D016385:TATA Box / Q000235:genetics; D014158:Transcription, Genetic / Q000502:physiology; D014407:Tumor Cells, Cultured
D005685:Galactans; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D012333:RNA, Messenger; C044347:1,6-galactan