background:
POU domain proteins contain a bipartite DNA-binding domain divided by a flexible linker that enables them to adopt various monomer configurations on DNA. The versatility of POU protein operation is additionally conferred at the dimerization level. The POU dimer from the OCT1 gene formed on the palindromic OCT factor recognition element, or PORE (ATTTGAAATGCAAAT), could recruit the transcriptional coactivator OSF1. Studies of tissue-specific expression of immunoglobulin promoters demonstrate the importance of an octamer, ATTTGCAT, and the proteins that bind to it. This is a regulatory element important for tissue- and cell-specific transcription as well as for transcription of a number of housekeeping genes. Oct-1 encodes one protein, NF-A1, which is found in nuclear extracts from all cell types and thus is not specific to lymphoid cells as is the protein NF-A2, which is encoded by Oct-2. A novel protein designated Bob 1 (B cell Oct binding protein 1), alternatively called OSF-1, specifically interacts with Oct-1 and Oct-2, enhancing their transcriptional efficacy. Bob 1 is expressed at highest levels in spleen and peripheral blood leukocytes and represents an Oct co-factor capable of conferring cell-specific activation of Oct-1 and Oct-2. Although having no intrinsic capacity for DNA binding, Bob 1 associates tightly with the octamer motif in the presence of Oct-1 and/or Oct-2. The gene which encodes Bob 1 maps to human chromosome 11q23.1.
Function:
Transcriptional coactivator that specifically associates with either OCT1 or OCT2. It boosts the OCT1 mediated promoter activity and to a lesser extent, that of OCT2. It has no intrinsic DNA-binding activity. It recognizes the POU domains of OCT1 and OCT2. It is essential for the response of B-cells to antigens and required for the formation of germinal centers.
Subcellular Location:
Nucleus.
Tissue Specificity:
B-cell specific.
Post-translational modifications:
Ubiquitinated; mediated by SIAH1 or SIAH2 and leading to its subsequent proteasomal degradation.
DISEASE:
Note=A chromosomal aberration involving POU2AF1/OSF1 may be a cause of a form of B-cell leukemia. Translocation t(3;11)(q27;q23) with BCL6.
Similarity:
Belongs to the POU2AF1 family.
Database links:
Entrez Gene: 451537 Chimpanzee
Entrez Gene: 528475 Cow
Entrez Gene: 489413 Dog
Entrez Gene: 101129955 Gorilla
Entrez Gene: 100070302 Horse
Entrez Gene: 5450 Human
Entrez Gene: 100394635 Marmoset (common)
Entrez Gene: 100437190 Orangutan
Omim: 601206 Human
SwissProt: Q2KJA4 Cow
SwissProt: Q16633 Human
Unigene: 654525 Human
Important Note:
This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications.
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