POU2AF1
Domain
In the N-terminus possesses a conserved OCA domain for bivalent binding to class II POU domain-containing transcription factors and to an octamer DNA motif.
Function
Transcriptional coactivator that specifically associates with either POU2F1/OCT1 or POU2F2/OCT2 (PubMed:7859290). It boosts the POU2F1/OCT1 mediated promoter activity and to a lesser extent, that of POU2F2/OCT2 (PubMed:7779176). It recognizes the POU domains of POU2F1/OCT1 and POU2F2/OCT2 (PubMed:7779176). It is essential for the response of B-cells to antigens and required for the formation of germinal centers (PubMed:7623806, PubMed:7859290). Regulates IL6 expression in B cells as POU2F2/OCT2 coactivator (By similarity).
Involvement in disease
A chromosomal aberration involving POU2AF1/OBF1 may be a cause of a form of B-cell leukemia. Translocation t(3;11)(q27;q23) with BCL6.
Post-translational modifications
Ubiquitinated; mediated by SIAH1 or SIAH2 and leading to its subsequent proteasomal degradation.
Sequence Similarities
Belongs to the POU2AF family.
Tissue Specificity
B-cell specific (PubMed:7779176, PubMed:7859290). Detected in mainly in spleen, but also in thymus, periphral blood leukocyte and small intestine (PubMed:7779176, PubMed:7859290).
Cellular localization
- Nucleus
Alternative names
BOB1, OBF1, POU2AF1, POU domain class 2-associating factor 1, B-cell-specific coactivator OBF-1, BOB-1, OCA-B, OCT-binding factor 1