Biology:TBX1
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T-box transcription factor TBX1 also known as T-box protein 1 and testis-specific T-box protein is a protein that in humans is encoded by the TBX1 gene.[1] Genes in the T-box family are transcription factors that play important roles in the formation of tissues and organs during embryonic development.[2] To carry out these roles, proteins made by this gene family bind to specific areas of DNA called T-box binding element (TBE)[2] to control the expression of target genes.
Gene
The TBX1 gene is located on the long (q) arm of chromosome 22 at position 11.21, from base pair 18,118,779 to base pair 18,145,669.[1]
Function
The T-box 1 protein appears to be necessary for the normal development of large arteries that carry blood out of the heart, muscles and bones of the face and neck, and glands such as the thymus and parathyroid.[3][4] Although the T-box 1 protein acts as a transcription factor, it is not yet known which genes are regulated by the protein.
TBX1 is thought to operate on the same developmental pathway as CHD7 which can be mutated in CHARGE syndrome. [5]
Clinical significance
Most cases of 22q11.2 deletion syndrome are caused by the deletion of a small piece of chromosome 22. This region of the chromosome contains about 30 genes, including the TBX1 gene. In a small number of affected individuals without a chromosome 22 deletion, mutations in the TBX1 gene are thought to be responsible for the characteristic signs and symptoms of the syndrome. Of the three known mutations, two mutations change one amino acid (a building block of proteins) in the T-box 1 protein. The third mutation deletes a single amino acid from the protein. These mutations likely disrupt the ability of the T-box 1 protein to bind to DNA and regulate the activity of other genes.[6][7][8]
Loss of the TBX1 gene, due to either a mutation in the gene or a deletion of part of chromosome 22, is responsible for many of the features of 22q11.2 deletion syndrome. Specifically, a loss of the TBX1 gene is associated with heart defects, an opening in the roof of the mouth (a cleft palate), distinctive facial features, and low calcium levels, but does not appear to cause learning disabilities.[9][10]
Mutation in TBX1 causes predisposition to hernias.[11]
References
- ↑ 1.0 1.1 "Entrez Gene: T-box 1". https://www.ncbi.nlm.nih.gov/gene/6899.
- ↑ 2.0 2.1 "An ancient family of embryonically expressed mouse genes sharing a conserved protein motif with the T locus". Nature Genetics 7 (3): 383–389. July 1994. doi:10.1038/ng0794-383. PMID 7920656.
- ↑ "DiGeorge syndrome phenotype in mice mutant for the T-box gene, Tbx1". Nature Genetics 27 (3): 286–291. March 2001. doi:10.1038/85845. PMID 11242110.
- ↑ "Tbx1 haploinsufficieny in the DiGeorge syndrome region causes aortic arch defects in mice". Nature 410 (6824): 97–101. March 2001. doi:10.1038/35065105. PMID 11242049.
- ↑ "Chromatin regulators in the TBX1 network confer risk for conotruncal heart defects in 22q11.2DS". npj Genomic Medicine 8 (1): 17. July 2023. doi:10.1038/s41525-023-00363-y. PMID 37463940.
- ↑ "DiGeorge's syndrome: a gene at last". Lancet 362 (9393): 1342–1343. October 2003. doi:10.1016/S0140-6736(03)14671-5. PMID 14585631.
- ↑ "DiGeorge syndrome: an update". Current Opinion in Cardiology 19 (3): 201–204. May 2004. doi:10.1097/00001573-200405000-00002. PMID 15096950.
- ↑ "Role of TBX1 in human del22q11.2 syndrome". Lancet 362 (9393): 1366–1373. October 2003. doi:10.1016/S0140-6736(03)14632-6. PMID 14585638.
- ↑ "T-box genes in human disorders". Human Molecular Genetics. 12 12 Spec No 1 (Spec No 1): R37–R44. April 2003. doi:10.1093/hmg/ddg077. PMID 12668595.
- ↑ "Unraveling the genetic and developmental mysteries of 22q11 deletion syndrome". Trends in Molecular Medicine 9 (9): 383–389. September 2003. doi:10.1016/S1471-4914(03)00141-2. PMID 13129704.
- ↑ "Genetic analysis of the TBX1 gene promoter in indirect inguinal hernia". Gene 535 (2): 290–293. February 2014. doi:10.1016/j.gene.2013.11.012. PMID 24295890.
Further reading
- "Chimeric negative regulation of p14ARF and TBX1 by a t(9;22) translocation associated with melanoma, deafness, and DNA repair deficiency". Human Mutation 34 (9): 1250–1259. September 2013. doi:10.1002/humu.22354. PMID 23661601.
External links
- TBX1+protein,+human at the US National Library of Medicine Medical Subject Headings (MeSH)
- Online Mendelian Inheritance in Man (OMIM) 602054
- EntrezGene 6899
- GeneCard for TBX1
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
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