Demonstration of a divergent transcript from the bidirectional heavy chain immunoglobulin promoter VH441 in B-cells.
AUTOR(ES)
Nguyen, Q T
RESUMO
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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=328896Documentos Relacionados
- The conserved decanucleotide from the immunoglobulin heavy chain promoter induces a very high transcriptional activity in B-cells when introduced into an heterologous promoter.
- Bidirectional transcription from the human immunoglobulin VH6 gene promoter.
- Properties and calcium-dependent inactivation of calcium currents in cultured mouse pancreatic B-cells.
- Sequence dependent hypermutation of the immunoglobulin heavy chain in cultured B cells
- Protein kinase A-dependent and -independent stimulation of exocytosis by cAMP in mouse pancreatic B-cells.