Abstract
Spi-B and PU.1 are hematopoietic-specific transcription factors that constitute a subfamily of the Ets family of DNA-binding proteins. Here we show that contrary to previous reports, PU.1 and Spi-B have very different expression patterns. PU.1 is expressed at high levels in B cells, mast cells, megakaryocytes, macrophages, neutrophils, and immature erythroid cells and at lower levels in mature erythrocytes. PU.1 is completely absent from peripheral T cells and most T cell lines based on sensitive RT-PCR assays. In contrast, Spi-B is expressed exclusively in lymphoid cells and can be detected in early fetal thymus and spleen. In situ hybridizations of adult murine tissues demonstrate Spi-B mRNA in the medulla of the thymus, the white pulp of the spleen, and the germinal centers of lymph nodes. Spi-B expression is very abundant in B cells and both Spi-B mRNA and protein are detected in some T cells. In situ hybridization and Northern blot analysis suggest that Spi-B gene expression increases during B cell maturation and decreases during T cell maturation. Gel-retardation experiments show that Spi-B can bind to all putative PU.1 binding sites, but do not reveal any preferred Spi-B binding site. Finally, both PU.1 and Spi-B function as transcriptional activators of the immunoglobulin light- chain enhancer E lambda 2.4 when coexpressed with Pip (PU.1-interaction partner) in NIH-3T3 cells. Taken together, these data suggest that differences in patterns of expression between Spi-B and PU.1 distinguish the function of each protein during development of the immune system.
Full Text
The Full Text of this article is available as a PDF (6.5 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baier T. G., Jenne E. W., Blum W., Schönberg D., Hartmann K. K. Influence of antibodies against IGF-I, insulin or their receptors on proliferation of human acute lymphoblastic leukemia cell lines. Leuk Res. 1992 Aug;16(8):807–814. doi: 10.1016/0145-2126(92)90160-9. [DOI] [PubMed] [Google Scholar]
- Corcoran L. M., Karvelas M., Nossal G. J., Ye Z. S., Jacks T., Baltimore D. Oct-2, although not required for early B-cell development, is critical for later B-cell maturation and for postnatal survival. Genes Dev. 1993 Apr;7(4):570–582. doi: 10.1101/gad.7.4.570. [DOI] [PubMed] [Google Scholar]
- Corcoran L. M., Karvelas M. Oct-2 is required early in T cell-independent B cell activation for G1 progression and for proliferation. Immunity. 1994 Nov;1(8):635–645. doi: 10.1016/1074-7613(94)90035-3. [DOI] [PubMed] [Google Scholar]
- Crepieux P., Coll J., Stehelin D. The Ets family of proteins: weak modulators of gene expression in quest for transcriptional partners. Crit Rev Oncog. 1994;5(6):615–638. [PubMed] [Google Scholar]
- Eisenbeis C. F., Singh H., Storb U. PU.1 is a component of a multiprotein complex which binds an essential site in the murine immunoglobulin lambda 2-4 enhancer. Mol Cell Biol. 1993 Oct;13(10):6452–6461. doi: 10.1128/mcb.13.10.6452. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenbeis C. F., Singh H., Storb U. Pip, a novel IRF family member, is a lymphoid-specific, PU.1-dependent transcriptional activator. Genes Dev. 1995 Jun 1;9(11):1377–1387. doi: 10.1101/gad.9.11.1377. [DOI] [PubMed] [Google Scholar]
- Galson D. L., Hensold J. O., Bishop T. R., Schalling M., D'Andrea A. D., Jones C., Auron P. E., Housman D. E. Mouse beta-globin DNA-binding protein B1 is identical to a proto-oncogene, the transcription factor Spi-1/PU.1, and is restricted in expression to hematopoietic cells and the testis. Mol Cell Biol. 1993 May;13(5):2929–2941. doi: 10.1128/mcb.13.5.2929. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Georgopoulos K., Bigby M., Wang J. H., Molnar A., Wu P., Winandy S., Sharpe A. The Ikaros gene is required for the development of all lymphoid lineages. Cell. 1994 Oct 7;79(1):143–156. doi: 10.1016/0092-8674(94)90407-3. [DOI] [PubMed] [Google Scholar]
- Heydemann A., Juang G., Hennessy K., Parmacek M. S., Simon M. C. The myeloid-cell-specific c-fes promoter is regulated by Sp1, PU.1, and a novel transcription factor. Mol Cell Biol. 1996 Apr;16(4):1676–1686. doi: 10.1128/mcb.16.4.1676. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hromas R., Orazi A., Neiman R. S., Maki R., Van Beveran C., Moore J., Klemsz M. Hematopoietic lineage- and stage-restricted expression of the ETS oncogene family member PU.1. Blood. 1993 Nov 15;82(10):2998–3004. [PubMed] [Google Scholar]
- Hugo P., Kappler J. W., Marrack P. C. Positive selection of TcR alpha beta thymocytes: is cortical thymic epithelium an obligatory participant in the presentation of major histocompatibility complex protein? Immunol Rev. 1993 Oct;135:133–155. doi: 10.1111/j.1600-065x.1993.tb00647.x. [DOI] [PubMed] [Google Scholar]
- Klemsz M. J., McKercher S. R., Celada A., Van Beveren C., Maki R. A. The macrophage and B cell-specific transcription factor PU.1 is related to the ets oncogene. Cell. 1990 Apr 6;61(1):113–124. doi: 10.1016/0092-8674(90)90219-5. [DOI] [PubMed] [Google Scholar]
- Kuratani S., Martin J. F., Wawersik S., Lilly B., Eichele G., Olson E. N. The expression pattern of the chick homeobox gene gMHox suggests a role in patterning of the limbs and face and in compartmentalization of somites. Dev Biol. 1994 Feb;161(2):357–369. doi: 10.1006/dbio.1994.1037. [DOI] [PubMed] [Google Scholar]
- Moulton K. S., Semple K., Wu H., Glass C. K. Cell-specific expression of the macrophage scavenger receptor gene is dependent on PU.1 and a composite AP-1/ets motif. Mol Cell Biol. 1994 Jul;14(7):4408–4418. doi: 10.1128/mcb.14.7.4408. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perez C., Coeffier E., Moreau-Gachelin F., Wietzerbin J., Benech P. D. Involvement of the transcription factor PU.1/Spi-1 in myeloid cell-restricted expression of an interferon-inducible gene encoding the human high-affinity Fc gamma receptor. Mol Cell Biol. 1994 Aug;14(8):5023–5031. doi: 10.1128/mcb.14.8.5023. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pevny L., Simon M. C., Robertson E., Klein W. H., Tsai S. F., D'Agati V., Orkin S. H., Costantini F. Erythroid differentiation in chimaeric mice blocked by a targeted mutation in the gene for transcription factor GATA-1. Nature. 1991 Jan 17;349(6306):257–260. doi: 10.1038/349257a0. [DOI] [PubMed] [Google Scholar]
- Pongubala J. M., Nagulapalli S., Klemsz M. J., McKercher S. R., Maki R. A., Atchison M. L. PU.1 recruits a second nuclear factor to a site important for immunoglobulin kappa 3' enhancer activity. Mol Cell Biol. 1992 Jan;12(1):368–378. doi: 10.1128/mcb.12.1.368. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ray-Gallet D., Mao C., Tavitian A., Moreau-Gachelin F. DNA binding specificities of Spi-1/PU.1 and Spi-B transcription factors and identification of a Spi-1/Spi-B binding site in the c-fes/c-fps promoter. Oncogene. 1995 Jul 20;11(2):303–313. [PubMed] [Google Scholar]
- Ray D., Bosselut R., Ghysdael J., Mattei M. G., Tavitian A., Moreau-Gachelin F. Characterization of Spi-B, a transcription factor related to the putative oncoprotein Spi-1/PU.1. Mol Cell Biol. 1992 Oct;12(10):4297–4304. doi: 10.1128/mcb.12.10.4297. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robb L., Lyons I., Li R., Hartley L., Köntgen F., Harvey R. P., Metcalf D., Begley C. G. Absence of yolk sac hematopoiesis from mice with a targeted disruption of the scl gene. Proc Natl Acad Sci U S A. 1995 Jul 18;92(15):7075–7079. doi: 10.1073/pnas.92.15.7075. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scott E. W., Simon M. C., Anastasi J., Singh H. Requirement of transcription factor PU.1 in the development of multiple hematopoietic lineages. Science. 1994 Sep 9;265(5178):1573–1577. doi: 10.1126/science.8079170. [DOI] [PubMed] [Google Scholar]
- Shin M. K., Koshland M. E. Ets-related protein PU.1 regulates expression of the immunoglobulin J-chain gene through a novel Ets-binding element. Genes Dev. 1993 Oct;7(10):2006–2015. doi: 10.1101/gad.7.10.2006. [DOI] [PubMed] [Google Scholar]
- Shinkai Y., Rathbun G., Lam K. P., Oltz E. M., Stewart V., Mendelsohn M., Charron J., Datta M., Young F., Stall A. M. RAG-2-deficient mice lack mature lymphocytes owing to inability to initiate V(D)J rearrangement. Cell. 1992 Mar 6;68(5):855–867. doi: 10.1016/0092-8674(92)90029-c. [DOI] [PubMed] [Google Scholar]
- Shivdasani R. A., Mayer E. L., Orkin S. H. Absence of blood formation in mice lacking the T-cell leukaemia oncoprotein tal-1/SCL. Nature. 1995 Feb 2;373(6513):432–434. doi: 10.1038/373432a0. [DOI] [PubMed] [Google Scholar]
- Simon M. C., Pevny L., Wiles M. V., Keller G., Costantini F., Orkin S. H. Rescue of erythroid development in gene targeted GATA-1- mouse embryonic stem cells. Nat Genet. 1992 May;1(2):92–98. doi: 10.1038/ng0592-92. [DOI] [PubMed] [Google Scholar]
- Winandy S., Wu P., Georgopoulos K. A dominant mutation in the Ikaros gene leads to rapid development of leukemia and lymphoma. Cell. 1995 Oct 20;83(2):289–299. doi: 10.1016/0092-8674(95)90170-1. [DOI] [PubMed] [Google Scholar]
- Zhang D. E., Hetherington C. J., Chen H. M., Tenen D. G. The macrophage transcription factor PU.1 directs tissue-specific expression of the macrophage colony-stimulating factor receptor. Mol Cell Biol. 1994 Jan;14(1):373–381. doi: 10.1128/mcb.14.1.373. [DOI] [PMC free article] [PubMed] [Google Scholar]