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).
Involvement in disease
May be involved in murine acute Friend erythroleukemia. It is a target region for SFFV proviral insertion.
Sequence Similarities
Belongs to the ETS family.
Tissue Specificity
Expressed in spleen, thymus and bone-marrow macrophages.
Cellular localization
- Nucleus
Alternative names
Sfpi-1, Sfpi1, Spi1, Transcription factor PU.1, 31 kDa-transforming protein, SFFV proviral integration 1 protein