Disease relevance of Pou2f2

• When the immunoglobulin-producing myeloma MPC11 is fused to a T lymphoma, Oct-2 production ceases, as does the expression of immunoglobulin, J chain, and several other B cell-specific gene products [1].
• When tested in a mouse plasmacytoma cell line, catfish Oct2 alpha and Oct2 beta, as well as mouse Oct2, showed higher transcriptional activation with the variant, as compared to the consensus, octamer motif [2].

High impact information on Pou2f2

• To determine whether Oct-2 is required for B-cell development or function, or has other developmental roles, the gene was disrupted by homologous recombination [3].
• Oct-2, a POU homeo domain transcription factor, is believed to stimulate B-cell-restricted expression of immunoglobulin genes through binding sites in immunoglobulin gene promoters and enhancers [3].
• Thus, Oct-2 is not required for the generation of immunoglobulin-bearing B cells but is crucial for their maturation to immunoglobulin-secreting cells and for another undetermined organismal function [3].
• Oct-2, although not required for early B-cell development, is critical for later B-cell maturation and for postnatal survival [3].
• Within this shared POU (Pit-1, Oct-1 and Oct-2, unc-86) domain (pronounced 'pow') lie two subdomains: a POU-related homeo box and a POU-specific box [4].

Biological context of Pou2f2

• In situ hybridization studies during mouse embryogenesis show that the Oct2 gene is widely expressed in the developing nervous system [5].
• The Oct2b cDNA has an insertion of 74 bp close to the 3' end which creates an open reading frame distinct from Oct2a [5].
• This suggests that Oct-2 plays a central role in maintaining the gene expression program of these cells [6].
• Remarkably, if we sustain Oct-2 expression during cell fusion, all the other tissue-specific genes of the Ig-secreting cell simultaneously escape silencing [6].
• The requirement for Oct-2 maps to an early activation step in G1, during which B cells make the commitment to progress through the cell cycle and to divide [7].

Anatomical context of Pou2f2

• The octamer motif ATGCAAAT is recognized indistinguishably by two mammalian transcription factors: one that is expressed ubiquitously and referred to here as Oct-1, and another, Oct-2, that is expressed in lymphoid cells [4].
• RNA analysis demonstrates that both Oct2a and 2b mRNAs are most abundant in B-cells but they are also expressed in a variety of tissues including brain, intestine, testis, kidney, as well as in embryos [5].
• Oct2 proteins are present in both neuronal and oligodendroglial cells, although they are more abundant in glial cells [5].
• Constitutively expressed Oct-2 prevents immunoglobulin gene silencing in myeloma x T cell hybrids [1].
• In the present study, we show that by preventing the loss of Oct-2 in the hybrid cells, we can preserve expression of all other tested B cell-specific genes [1].

Associations of Pou2f2 with chemical compounds

• Induction of pre-B cells with lipopolysaccharide led to increased Oct2 levels but did not significantly increase octamer-dependent transcription in BOB.1 / OBF.1-deficient B cells [8].
• The higher expression of Oct2 in male mice is due to testosterone [9].
• Oct-2, a POU homeodomain protein expressed primarily in B cells, is a powerful transcriptional activator that binds to DNA at sites appropriately placed for major effects on immunoglobulin gene expression [7].
• Oct-2 mRNA induction during antigen-driven T-cell activation was blocked by cyclosporin A, as well as by protein synthesis inhibitors [10].
• In null mutants, capsaicin sensitivity, and neuropeptide and cytoskeletal protein expression were unaffected by the loss of Oct-2 expression [11].

Physical interactions of Pou2f2

• As a result, the Oct2b protein has a carboxy end which is similar to that of the ubiquitous octamer-binding protein Oct1 [5].

Regulatory relationships of Pou2f2

• These findings support the notion that Oct-2 regulates gene transcription by both OBF-1-dependent and -independent mechanisms [12].
• Our results demonstrate that in these Oct2-deficient B cells the ubiquitous endogenous Oct1 protein is able to stimulate octamer-containing promoters to a level comparable with that of normal Oct2-positive B cells [13].

Other interactions of Pou2f2

• Using restriction fragment length variants (RFLVs) in interspecific backcross mice between Mus musculus (C3H strain) and Mus spretus, the Trsp gene was mapped to the proximal region of mouse Chr 7, cosegregating with octamer-binding transcription factor-2 (Otf2) [14].
• This octamer element can be bound by either Oct-1 or Oct-2 but requires the expression of Oct-2 to activate transcription in B cells [12].
• However, expression of only a single gene, the murine CD36 gene, has been shown to date to be dependent on Oct2 [15].
• Molecular probes for Otf-1 and Otf-2 recognized single loci on mouse chromosomes 1 and 7, respectively, whereas probes for Otf-3 recognized a minimum of eight independently segregating loci (designated Otf-3a through Otf-3h) [16].
• Two variant octamer motifs were identified in the upstream promoter region of the crisp-3 gene, and Oct2 interacts with both of them in vitro [15].

Analytical, diagnostic and therapeutic context of Pou2f2

• In this study, we describe mice in which the endogenous oct-2 gene has been modified through gene targeting to create a mutated allele, oct-2DeltaC, which encodes Oct-2 protein isoforms that lack all sequence C-terminal to the DNA-binding domain [17].
• Northern blots show that central nervous tissue contains a larger than normal (> 10 kb) mRNA transcript corresponding in size to an Oct-2 transcript encoding a defective protein [11].
• The DNA-binding (POU) domain of the catfish Oct2 transcription factor was shown, by electromobility shift assays and surface plasmon resonance techniques, to have an affinity for the consensus octamer motif (ATGCAAAT) that was slightly higher than its affinity for a variant motif (ATGtAAAT) [2].
• PCR analysis shows the absence of normal Oct-2 transcripts in dorsal root ganglia [11].
• Absence of Oct2 in itself had little effect on the pharmacokinetics of tetraethylammonium (TEA), but in Oct1/2(-/-) mice, renal secretion of this compound was completely abolished, leaving only glomerular filtration as a TEA clearance mechanism [18].

References