Analysis of Oct2-isoform expression in lipopolysaccharide-stimulated B lymphocytes.
Oct2-isoform expression in splenic B cells stimulated with lipopolysaccharide or lipopolysaccharide plus phorbol-di-butyrate was analysed by cDNA cloning. The frequency of Oct2-positive clones was 1/15,000 in both libraries. Two new isoforms were found that generate novel amino- or carboxy-terminal sequences. An isoform lacking exon 11 destroyed the carboxy-terminal leucin-zipper region and introduced a frame shift creating a novel, proline-rich carboxy terminus. A new exon containing a highly basic region (4c) was characterized, between exons 4 and 5. This exon was inserted between glutamine-rich regions 2 and 3, carboxy terminal of a tentative leucine-zipper structure. In addition, a new combination isoform containing Oct2a's amino terminal insert (exon 7a) and Oct2b's carboxy terminal insert (exon 13) was found that created a novel large isoform, Oct2ab. More frequent use of the classical Oct2a and Oct2b isoforms was observed in the lipopolysaccharide-stimulated B cells, while a preference for the Oct2ab and Oct2ba isoforms was observed in lipopolysaccharide plus phorbol-di-butyrate-treated cells.
Johansson
K
K
Immunology Unit, University of Lund, Sweden.
Sigvardsson
M
M
Leanderson
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism / Q000502:physiology*; D001483:Base Sequence; D002454:Cell Differentiation / Q000502:physiology; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000737:chemistry* / Q000502:physiology; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D050813:Octamer Transcription Factor-2; D016133:Polymerase Chain Reaction; D014157:Transcription Factors / Q000096:biosynthesis* / Q000737:chemistry* / Q000502:physiology
D004268:DNA-Binding Proteins; D008070:Lipopolysaccharides; D050813:Octamer Transcription Factor-2; C058435:POU2F2 protein, human; C489206:Pou2f2 protein, mouse; D014157:Transcription Factors