Spi-C, a novel Ets protein that is temporally regulated during B lymphocyte development.
A novel Ets protein was isolated by yeast one-hybrid screening of a cDNA library made from lipopolysaccharide-stimulated mouse splenic B cells, using the SP6 kappa promoter kappaY element as a bait. The novel Ets protein was most closely related to PU.1 and Spi-B within the DNA binding Ets domain and was therefore named Spi-C. However, Spi-C may represent a novel subgroup within the Ets protein family, as it differed significantly from Spi-B and PU.1 within helix 1 of the Ets domain. Spi-C was encoded by a single-copy gene that was mapped to chromosome 10, region C. Spi-C interacted with DNA similarly to PU.1 as judged by methylation interference, band-shift and site selection analysis, and activated transcription of a kappaY element reporter gene upon co-transfection of HeLa cells. Spi-C RNA was expressed in mature B lymphocytes and at lower levels in macrophages. Furthermore, pre-B cell and plasma cell lines were Spi-C-negative, suggesting that Spi-C might be a regulatory molecule during a specific phase of B lymphoid development.
Bemark
M
M
Immunology Unit, Department of Cell and Molecular Biology, Lund University, P. O. Box 7031, S-220 07 Lund, Sweden.
Mårtensson
A
A
Liberg
D
D
Leanderson
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D002454:Cell Differentiation; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D015536:Down-Regulation; D017930:Genes, Reporter; D006367:HeLa Cells; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000187:drug effects; D015534:Trans-Activators / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D015533:Transcriptional Activation; D000099232:Proto-Oncogene Protein Spi-1
D004247:DNA; D012321:DNA-Directed RNA Polymerases; D007145:Immunoglobulin kappa-Chains; D008070:Lipopolysaccharides; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1; C070852:RNA polymerase SP6