Protein BTG1 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''BTG1''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Function

The BTG1 gene locus has been shown to be involved in a t(8;12)(q24;q22)

chromosomal translocation In genetics, chromosome translocation is a phenomenon that results in unusual rearrangement of chromosomes. This includes balanced and unbalanced translocation, with two main types: reciprocal-, and Robertsonian translocation. Reciprocal translo ...

in a case of

B-cell chronic lymphocytic leukemia Chronic lymphocytic leukemia (CLL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). Early on, there are typically no symptoms. Later, non-painful lymph node swelling, feeling tired, fever, nigh ...

. It is a member of a family of antiproliferative genes. BTG1 expression is maximal in the G0/G1 phases of the

cell cycle The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subs ...

and downregulated when cells progressed through G1. It negatively regulates

cell proliferation Cell proliferation is the process by which ''a cell grows and divides to produce two daughter cells''. Cell proliferation leads to an exponential increase in cell number and is therefore a rapid mechanism of tissue growth. Cell proliferation re ...

Interactions

BTG1 has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...

with: *

CNOT7 CCR4-NOT transcription complex subunit 7 is a protein that in humans is encoded by the ''CNOT7'' gene. It is a subunit of the CCR4-Not deadenylase complex. Function The protein encoded by this gene binds to an anti-proliferative protein, B-ce ...

, *

CNOT8 CCR4-NOT transcription complex subunit 8 is a protein that in humans is encoded by the ''CNOT8'' gene. It is a subunit of the CCR4-Not deadenylase complex. Interactions CNOT8 has been shown to interact with BTG2, BTG1, CNOT1 and CNOT3 CCR ...

, *

HOXB9 Homeobox protein Hox-B9 is a protein that in humans is encoded by the ''HOXB9'' gene. Function This gene is a member of the Abd-B homeobox family and encodes a protein with a homeobox DNA-binding domain. It is included in a cluster of homeobox ...

, and *

PRMT1 Protein arginine N-methyltransferase 1 is an enzyme that in humans is encoded by the ''PRMT1'' gene. The HRMT1L2 gene encodes a protein arginine methyltransferase that functions as a histone methyltransferase specific for histone H4. Function ...

Clinical relevance

Recurrent mutations in this gene have been associated to cases of

diffuse large B-cell lymphoma Diffuse large B-cell lymphoma (DLBCL) is a cancer of B cells, a type of lymphocyte that is responsible for producing antibody, antibodies. It is the most common form of non-Hodgkin lymphoma among adults, with an annual Incidence (epidemiology), in ...

Maintenance of adult neural stem cells

Recent data, obtained in a new model of mouse lacking the BTG1 gene, indicate that BTG1 is essential for the proliferation and expansion of stem cells in the adult neurogenic niches, i.e. the

dentate gyrus The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum. The dentate gyrus is part of the hippocampal trisynaptic circuit and is thought to contribute ...

and sub ventricular zone (see for review). In particular, BTG1 keeps adult neural stem cells in quiescence, preserving the neural stem cells pool from depletion. In the absence of BTG1, the stem and progenitor cells initially hyper proliferate and then in the longer period lose the ability to proliferate and expand. Other recent data indicate that physical exercise can fully reconstitute the proliferative defect of stem cells that follows the ablation of the BTG1 gene, suggesting that the pool of neural stem cells maintains a hidden form of plasticity which is tightly controlled by BTG1; hence, BTG1 might prevent the depletion of stem cells in the presence of strong neurogenic stimuli or of neural degenerative stimuli. Btg1 plays a role also in the expansion of cerebellar granule precursor cells. In fact the deletion of Btg1 leads in mouse to uncontrolled proliferation of the cerebellar precursor cells during the early postnatal period. Consequently, in the adult, the cerebellum lacking Btg1 is significantly larger and the motor coordination is heavily impaired. The closest homolog of BTG1 is BTG2, which also controls the proliferation and differentiation of adult neural stem cells; the role of BTG2, however, appears to differ from that of BTG1 being probably more relevant in controlling the terminal differentiation of neural stem and progenitor cells in the adult neurogenic niches.

Function

Interactions

Clinical relevance

Maintenance of adult neural stem cells

References

External links

Further reading