BCL6

The protein encoded by this BCL6 gene is an evolutionarily conserved 95-kDa protein containing six C-terminal zinc-finger motifs and an N-terminal POZ domain. It has been reported that BCL6 is present in DNA-binding complexes in nuclear extracts from various B-cell lines. There are many relationships between non-Hodgkin's lymphoma, diffuse large cell lymphoma and BCL6's translocations. BCL6 can repress transcription from promoters linked to its DNA target sequence and this activity is dependent upon specific DNA-binding and the presence of an intact N-terminal half of the protein.

BCL6 Related Areas

Cancer>>Cancer Biomarkers>> BCL6

BCL6 Alternative Names

BCL5,BCL6A,LAZ3,ZBTB27,ZNF51,B-cell lymphoma 5 protein,B-cell lymphoma 6 protein [Homo sapiens]

Bcl5, B-cell leukemia,lymphoma 5, B-cell lymphoma 6 protein homolog [Mus musculus]

Summaries for BCL6

Entrez Gene summary for BCL6:

The protein encoded by this BCL6 gene is a zinc finger transcription factor and contains an N-terminal POZ domain. BCL6 protein acts as a sequence-specific repressor of transcription, and has been shown to modulate the transcription of START-dependent IL-4 responses of B cells. BCL6 protein can interact with a variety of POZ-containing proteins that function as transcription corepressors. This gene is found to be frequently translocated and hypermutated in diffuse large-cell lymphoma (DLCL), and may be involved in the pathogenesis of DLCL. Alternatively spliced transcript variants encoding different protein isoforms have been found for this gene. [provided by RefSeq, Sep 2008]

OMIM - description for BCL6:

BCL6 functions as a transcriptional repressor and is necessary for germinal center formation. Approximately 40% of diffuse large cell lymphomas and 5 to 10% of follicular lymphomas are associated with chromosomal translocations that deregulate expression of BCL6 by juxtaposing heterologous promoters to the BCL6 coding domain (Cattoretti et al., 1995).

Wikipedia summary for BCL6:

B-cell lymphoma 6 protein is a protein that in humans is encoded by the BCL6 gene.

Human BCL6 Protein General Information

 

• Protein names: B-cell lymphoma 6 protein, Short name=BCL-6
• Sequence length: 706 AA.
• Domain: The BTB domain mediates homodimerization. Its dimer interface mediates peptide binding such as to corepressors BCOR and NCOR2.
• Sequence similarities: BCL6 contains 1 BTB (POZ) domain. BCL6 contains 6 C2H2-type zinc fingers.
• Post-translational modification: BCL6 is phosphorylated by MAPK1 in response to antigen receptor activation at Ser-333 and Ser-343. Phosphorylation induces its degradation by ubiquitin/proteasome pathway.
  Polyubiquitinated. Polyubiquitination leads to degradation by the proteasome.
• Subunit structure: Homodimer. BCL6 interacts (via BTB domain) with BCOR; the interaction is direct. BCL6 interacts (via BTB domain) with NCOR2; the interaction is direct. BCL6 interacts with ZBTB7 and BCL6B By similarity. BCL6 interacts with the catalytic domain of HDAC9.
• Subcellular location: Nucleus
• Induction: Down-regulated during maturation of dendritic cells by selective stimuli such as bacterial lipopolysaccharides (LPS), CD40LG and zymosan.
• Tissue specificity: BCL6 is expressed in germinal center T and B-cells and in primary immature dendritic cells.
• Involvement in disease: Note=Chromosomal aberrations involving BCL6 may be a cause of B-cell non-Hodgkin lymphoma. Translocation t(3;14)(q27;q32); translocation t(3;22)(q27;q11) with immunoglobulin gene regions.
  Note=A chromosomal aberration involving BCL6 may be a cause of a form of B-cell leukemia. Translocation t(3;11)(q27;q23) with POU2AF1/OBF1.
  Note=A chromosomal aberration involving BCL6 may be a cause of lymphoma. Translocation t(3;4)(q27;p11) with ARHH/TTF.

General information above from UniProt

Function for BCL6 Protein

UniProtKB:

BCL6 is transcriptional repressor which is required for germinal center formation and antibody affinity maturation. BCL6 probably plays an important role in lymphomagenesis.

Genatlas:

• BCL6 is zinc finger transcriptional repressor or activator required for germinal center development and regulating B lymphocytes cell fate during the germinal center reaction by preventing terminal differentiation of B lymphocytes
• BCL6 supresses the expression of TP53 by binding two specific DNA sites in the p53 promoter region and modulates DNA damaged-induced apoptotic responses in germinal-centre B
• BCL6 recruits a SMRT/SIN3A/histone deacetylase complex to mediate transcriptional repression
• BCL6 regulates gene expression to control inflammation, lymphocyte differentiation, and lymphomagenesis through repression of AP-1
• BCL6 transcriptional repressor, implicated in the pathogenesis of lymphomas, especially the diffuse large B-cell type
• BCL6 is nuclear phosphoprotein that is the master regulator in germinal center (GC) formation and GC B-cell differentiation and survival
• BCL6 can also repress genes indirectly through binding to other transcription factors, such as peroxisome proliferator-activated receptor (PPARD and ZBTB17)
• BCL6 has an important function in facilitating apoptosis of germinal center B cells via suppression of BCL2, and blocking this pathway may be critical for lymphomagenesis)
• BCL6 can suppress target gene expression by directly binding to specific DNA sequences or by interacting with PIAS2 or AP1 factors, which in turn bind DNA direct
• BCL6 is required for programming of T follicular helper cell generation
• BCL6 is transcriptional repressor that is essential for the germinal center (GC) reaction and important in lymphomagenesis

Homology for human BCL6

• homolog to murine Bcl6
• homolog to rattus LOC303836

Phenotype Information for BCL6

• Gene/Locus: BCL6
• Phenotype: Lymphoma, B-cell

Phenotype Information for BCL6 from OMIM (Online Mendelian Inheritance in Man)