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Query: UMLS:C0265264 (HOS)
 1,119 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

T-box genes, in all metazoans studied from nematode to man, exist in small gene families. They encode transcription factors with a novel, large, and highly conserved DNA binding domain termed the T-domain. In all cases studied, T-box genes have important developmental roles. Two familial diseases, Holt-Oram syndrome and ulnar-mammary syndrome, were recently shown to be caused by mutations in the human T-box genes TBX5 and TBX3, respectively. T-box genes were first identified in Drosophila and mouse. Two of the three known Drosophila T-box genes show a close sequence homology to mammalian genes. Similarities in the phenotypes of fly and mammalian mutants can be taken as evidence of functional conservation. We report here the isolation of a fourth Drosophila T-box gene, optomotor-blind-related gene-1 (org-1), closely related to mouse and human TBX1. We localized TBX1 to chromosomal band 22q11, confirming a recent report, and discuss TBX1 as a candidate gene for DiGeorge and related syndromes.
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PMID:Isolation of a Drosophila T-box gene closely related to human TBX1. 961 Dec 67

Brachyury(T) is a mouse mutation, first described over 70 years ago, that causes defects in mesoderm formation. Recently several related genes, the T-box gene family, that encode a similar N-terminal DNA binding domain, the T-box, and that play critical roles in human embryonic development have been identified. It has been shown that human TBX5 and TBX3, if mutated, cause developmental disorders, Holt-Oram syndrome (OMIM 142900) and ulnar-mammary syndrome (OMIM 181450), respectively. We have identified four new human members of the T-box gene family, EOMES, TBX6, TBX18, and TBX19, and these genes have been mapped to different chromosomal regions by radiation hybrid mapping. The four T-box genes were classified into four different subfamilies and have also been subjected to phylogenomic analysis. Human EOMES maps at 3p21.3-p21.2. This Tbr1-subfamily gene is likely to play a significant role in early embryogenesis similar to that described for Xenopus eomesodermin. Human TBX6 maps at 16p12-q12. This Tbx6-subfamily gene is likely to participate in paraxial mesoderm formation and somitogenesis in human embryo. TBX18 is a novel member of the Tbx1 subfamily that maps at 6q14-q15. Two subgroups, TBX1/10 and TBX15/18 subgroups, could be distinguished within the Tbx1 subfamily. TBX19 is an orthologue of chick TbxT and maps at 1q23-q24. The genomic organization of TBX19 is highly similar to that of human T(Brachyury), another human member of the same subfamily.
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PMID:Identification, mapping, and phylogenomic analysis of four new human members of the T-box gene family: EOMES, TBX6, TBX18, and TBX19. 988 94

T-box genes encode transcription factors involved in morphogenesis and organogenesis of vertebrates and invertebrates. Mutations in human T-box genes TBX3, TBX5, and TBX1 cause severe genetic disorders known as Ulnar-Mammary syndrome (UMS), Holt-Oram syndrome (HOS), and DiGeorge syndrome, respectively. The crystal structure of the T-box domain of the first human T-box transcription factor, TBX3, in complex with DNA at 1.7 A resolution explains structural consequences of T-box domain point mutations observed in UMS and HOS patients. Comparison with the structure of the T-box domain from Xenopus laevis (Xbra) bound to DNA shows differences in several secondary structure elements and in the quaternary structure of the two complexes. TBX3 independently recognizes the two binding sites present in the palindromic DNA duplex, whereas in Xbra, binding to the palindrome is stabilized through interactions between the two monomers. The different quaternary structures suggest different DNA binding modes for T-box transcription factors.
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PMID:Structure of the DNA-bound T-box domain of human TBX3, a transcription factor responsible for ulnar-mammary syndrome. 1200 33

Ventricular septal defects (VSDs) are the most commonly occurring congenital heart defect. They are regularly associated with complex syndromes, including DiGeorge syndrome and Holt-Oram syndrome, which are characterised by haploinsufficiency for the T-box transcription factors TBX1 and TBX5, respectively. The histone acetyltransferase monocytic leukaemia zinc finger protein, MOZ (MYST3/KAT6A), is required for the expression of the Tbx1 and Tbx5 genes. Homozygous loss of MOZ results in DiGeorge syndrome-like defects including VSD. The Moz gene is expressed in the ectodermal, mesodermal and endodermal aspects of the developing pharyngeal apparatus and heart; however it is unclear in which of these tissues MOZ is required for heart development. The role of MOZ in the activation of Tbx1 would suggest a requirement for MOZ in the mesoderm, because deletion of Tbx1 in the mesoderm causes VSDs. Here, we investigated the tissue-specific requirements for MOZ in the mesoderm. We demonstrate that Mesp1-cre-mediated deletion of Moz results in high penetrance of VSDs and overriding aorta and a significant decrease in MOZ-dependant Tbx1 and Tbx5 expression. Together, our data suggest that the molecular pathogenesis of VSDs in Moz germline mutant mice is due to loss of MOZ-dependant activation of mesodermal Tbx1 and Tbx5 expression.
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PMID:Mesodermal expression of Moz is necessary for cardiac septum development. 2591 87