Recombinant Mouse Transcription factor PU.1 (Spi1)

Function

Pioneer transcription factor, which controls hematopoietic cell fate by decompacting stem cell heterochromatin and allowing other transcription factors to enter otherwise inaccessible genomic sites (PubMed:8079170). Once in open chromatin, can directly control gene expression by binding genetic regulatory elements and can also more broadly influence transcription by recruiting transcription factors, such as interferon regulatory factors (IRFs), to otherwise inaccessible genomic regions (By similarity). Transcriptionally activates genes important for myeloid and lymphoid lineages, such as CSF1R (By similarity). Transcriptional activation from certain promoters, possibly containing low affinity binding sites, is achieved cooperatively with other transcription factors. FCER1A transactivation is achieved in cooperation with GATA1 (By similarity). May be particularly important for the pro- to pre-B cell transition (PubMed:8079170). Binds (via the ETS domain) onto the purine-rich DNA core sequence 5'-GAGGAA-3', also known as the PU-box (PubMed:2180582). In vitro can bind RNA and interfere with pre-mRNA splicing (PubMed:8626664)

Subcellular Location

Nucleus

Disease Association

[May be involved in murine acute Friend erythroleukemia. It is a target region for SFFV proviral insertion]

Tissue Specificity

Expressed in spleen, thymus and bone-marrow macrophages

Subunit

Binds DNA as a monomer. Can form homomers (By similarity). Directly interacts with CEBPD/NF-IL6-beta; this interaction does not affect DNA-binding properties of each partner (PubMed:7594592). Interacts with NONO/p54(nrb) (PubMed:8626664). Interacts with RUNX1/AML1 (By similarity). Interacts with GFI1; the interaction represses SPI1 transcriptional activity, hence blocks SPI1-induced macrophage differentiation of myeloid progenitor cells (PubMed:17197705). Interacts with CEBPE (By similarity). Interacts with IRF4/Pip and IRF8 (By similarity). Interacts with JUN (By similarity). Interacts with RB1 (By similarity). Interacts with TBP (By similarity)

• Moreau-Gachelin F. et al. The putative oncogene Spi-1: murine chromosomal localization and transcriptional activation in murine acute erythroleukemias. — Oncogene (1989)
• Moreau-Gachelin F. et al. PubMed: CI-5AIOKPM4LL57N — Oncogene (1990)
• Klemsz M.J. et al. The macrophage and B cell-specific transcription factor PU.1 is related to the ets oncogene. — Cell (1990)
• Paul R. et al. The Sfpi-1 proviral integration site of Friend erythroleukemia encodes the ets-related transcription factor Pu.1. — J. Virol. (1991)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Nagulapalli S. et al. Multiple proteins physically interact with PU.1. Transcriptional synergy with NF-IL6 beta (C/EBP delta, CRP3). — J. Immunol. (1995)
• Hallier M. et al. The transcription factor Spi-1/PU.1 binds RNA and interferes with the RNA-binding protein p54nrb. — J. Biol. Chem. (1996)
• Dahl R. et al. The transcriptional repressor GFI-1 antagonizes PU.1 activity through protein-protein interaction. — J. Biol. Chem. (2007)