BCL6
Encyclopedia
B-cell lymphoma 6 protein is a protein
that in humans is encoded by the BCL6 gene
.
transcription factor and contains an N-terminal POZ/BTB domain. This protein acts as a sequence-specific repressor of transcription, and has been shown to modulate the STAT-dependent Interleukin 4
(IL-4) responses of B cells. This protein can interact with several corepressor complexes to inhibit transcription
. This gene is found to be frequently translocated and hypermutated in diffuse large B cell lymphoma
(DLBCL), and contributes to the pathogenesis of DLBCL. An exon 7 skipping splice variant encodes a shorter form of the protein which lacks the first two zinc fingers of the DNA binding domain.
. It is exclusively present in the B-cells of both healthy and neoplastic
germinal centres. It therefore demonstrates both reactive hyperplasia
in lymph nodes and a range of lymphoma
s derived from follicular B-cells, such as Burkitt's lymphoma
, follicular lymphoma
, and the nodular lymphocyte predominant subtype of Hodgkin's disease. It is often used together with antibodies to Bcl-2
antigen to distinguish neoplastic follicles from those found in benign hyperplasia, for which the latter is negative.
with
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that in humans is encoded by the BCL6 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Function
The protein encoded by this gene is an evolutionarily conserved zinc fingerZinc finger
Zinc fingers are small protein structural motifs that can coordinate one or more zinc ions to help stabilize their folds. They can be classified into several different structural families and typically function as interaction modules that bind DNA, RNA, proteins, or small molecules...
transcription factor and contains an N-terminal POZ/BTB domain. This protein acts as a sequence-specific repressor of transcription, and has been shown to modulate the STAT-dependent Interleukin 4
Interleukin 4
Interleukin-4, abbreviated IL-4, is a cytokine that induces differentiation of naive helper T cells to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4. The cell that initially produces IL-4, thus inducing Th0 differentiation, has not been identified, but recent...
(IL-4) responses of B cells. This protein can interact with several corepressor complexes to inhibit transcription
Transcription
Transcription may refer to:*Transcription , a business which converts speech into a written or electronic text document*Transcription , software which helps convert speech into text transcript...
. This gene is found to be frequently translocated and hypermutated in diffuse large B cell lymphoma
Diffuse large B cell lymphoma
Diffuse large B-cell lymphoma is a type of aggressive non-Hodgkin lymphoma. It accounts for approximately 40% of lymphomas among adults. The median age at diagnosis is 70 years, but it also occurs in children and young adults...
(DLBCL), and contributes to the pathogenesis of DLBCL. An exon 7 skipping splice variant encodes a shorter form of the protein which lacks the first two zinc fingers of the DNA binding domain.
Diagnostic utility
The presence of Bcl-6 can be demonstrated in tissue sections using immunohistochemistryImmunohistochemistry
Immunohistochemistry or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...
. It is exclusively present in the B-cells of both healthy and neoplastic
Neoplasia
Neoplasm is an abnormal mass of tissue as a result of neoplasia. Neoplasia is the abnormal proliferation of cells. The growth of neoplastic cells exceeds and is not coordinated with that of the normal tissues around it. The growth persists in the same excessive manner even after cessation of the...
germinal centres. It therefore demonstrates both reactive hyperplasia
Lymphoid hyperplasia
Lymphoid hyperplasia is the rapid growth proliferation of normal cells that resemble lymph tissue.-Lymph Node Anatomy:...
in lymph nodes and a range of lymphoma
Lymphoma
Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...
s derived from follicular B-cells, such as Burkitt's lymphoma
Burkitt's lymphoma
Burkitt's lymphoma is a cancer of the lymphatic system...
, follicular lymphoma
Follicular lymphoma
Follicular lymphoma is the most common of the indolent non-Hodgkin's lymphomas, and the second most common form of non-Hodgkin's lymphomas overall. It is defined as a lymphoma of follicle center B-cells , which has at least a partially follicular pattern...
, and the nodular lymphocyte predominant subtype of Hodgkin's disease. It is often used together with antibodies to Bcl-2
Bcl-2
Bcl-2 is the founding member of the Bcl-2 family of apoptosis regulator proteins encoded by the BCL2 gene. Bcl-2 derives its name from B-cell lymphoma 2, as it is the second member of a range of proteins initially described in chromosomal translocations involving chromosomes 14 and 18 in...
antigen to distinguish neoplastic follicles from those found in benign hyperplasia, for which the latter is negative.
Interactions
BCL6 has been shown to interactProtein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...
with
- BCORBCORBCL-6 corepressor is a protein that in humans is encoded by the BCOR gene.Mutations in the BCOR gene cause a form of syndromic microphthalmia called MCOPS2. This syndrome incorporates microphthalmia, congenital cataracts, cardiac defects, dental defects and skeletal anomalies...
, - C-junC-junc-Jun is the name of a gene and protein that, in combination with c-Fos, forms the AP-1 early response transcription factor. It was first identified as the Fos-binding protein p39 and only later rediscovered as the product of the c-jun gene. It is activated through double phosphorylation by the...
, - HDAC1HDAC1Histone deacetylase 1 is an enzyme that in humans is encoded by the HDAC1 gene.-Interactions:HDAC1 has been shown to interact with RAD9A, DNMT3L, MTA1, FKBP3, CDC20, CDH1, Host cell factor C1, BUB3, Nuclear receptor co-repressor 2, IKZF1, Prohibitin, EVI1, DDX5, DNMT3A, Mothers against...
, - HDAC4HDAC4Histone deacetylase 4, also known as HDAC4, is a protein which in humans is encoded by the HDAC4 gene.- Function :Histones play a critical role in transcriptional regulation, cell cycle progression, and developmental events. Histone acetylation/deacetylation alters chromosome structure and affects...
, - HDAC7AHDAC7AHistone deacetylase 7 is an enzyme that in humans is encoded by the HDAC7 gene.-Interactions:HDAC7A has been shown to interact with Endothelin receptor type A, HDAC3, HTATIP, BCL6, Nuclear receptor co-repressor 1 and IKZF1.-Further reading:...
, - HDAC5Histone deacetylase 5Histone deacetylase 5 is an enzyme that in humans is encoded by the HDAC5 gene.-Interactions:Histone deacetylase 5 has been shown to interact with Zinc finger and BTB domain-containing protein 16, BCL6, CBX5, YWHAQ, Myocyte-specific enhancer factor 2A, Nuclear receptor co-repressor 1, IKZF1,...
, - IRF4IRF4Interferon regulatory factor 4 is a protein that in humans is encoded by the IRF4 gene, also known as MUM1. In melanocytic cells the IRF4 gene may be regulated by MITF.-Interactions:IRF4 has been shown to interact with STAT6, NFATC2, BCL6 and SPI1....
, - NCOR2Nuclear receptor co-repressor 2The nuclear receptor co-repressor 2 is a transcriptional coregulatory protein that contains several nuclear receptor-interacting domains. In addition, NCOR2 appears to recruit histone deacetylases to DNA promoter regions. Hence NCOR2 assists nuclear receptors in the down regulation of target...
, - ZBTB7AZBTB7AZinc finger and BTB domain-containing protein 7A is a protein that in humans is encoded by the ZBTB7A gene.-Further reading:- External links :...
- ZBTB16Zinc finger and BTB domain-containing protein 16Zinc finger and BTB domain-containing protein 16 is a protein that in humans is encoded by the ZBTB16 gene.-Function:This gene is a member of the Krueppel C2H2-type zinc-finger protein family and encodes a zinc finger transcription factor that contains nine Kruppel-type zinc finger domains at the...
See also
- Nodular lymphocyte predominant Hodgkin's lymphomaNodular lymphocyte predominant Hodgkin's lymphomaNodular lymphocyte predominant Hodgkin's lymphoma is a form of lymphoma.It is no longer classified as a form of classic Hodgkin's lymphoma...
- Diffuse large B cell lymphomaDiffuse large B cell lymphomaDiffuse large B-cell lymphoma is a type of aggressive non-Hodgkin lymphoma. It accounts for approximately 40% of lymphomas among adults. The median age at diagnosis is 70 years, but it also occurs in children and young adults...