title: An alternatively spliced isoform of the Spi-B transcription factor.
abstract: Spi-B is an Ets transcription factor related to the oncoprotein Spi-1/PU.1 and highly expressed in B lymphoid cells. The Ets proteins share a conserved Ets domain that mediates specific DNA binding. Spi-B binds DNA sequences containing a core 5'-GGAA-3' and activates transcription through this motif. Up to date, the biological function of Spi-B remains unknown. Here, we describe the characterization of an alternatively spliced variant of Spi-B, named deltaSpi-B, which has lost the Ets domain. In B lymphoid cells, deltaspi-B and spi-B mRNAs were present simultaneously in a ratio of around 10%. DeltaSpi-B product was not able to bind DNA and was recovered in cytoplasmic cellular extracts. We raise the hypothesis that delta Spi-B might affect Spi-B function by recruiting factors involved in Spi-B activity.
authors.affiliation: INSERM U.248, Institut Curie, Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Ray-Gallet
authors.forename: A
authors.initials: A
authors.lastname: Tavitian
authors.forename: F
authors.initials: F
authors.lastname: Moreau-Gachelin
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D002051:Burkitt Lymphoma / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D005091:Exons; D015870:Gene Expression; D015698:Genomic Library; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014157:Transcription Factors; C076877:SPIB protein, human