TBX20
Encyclopedia
TBX20
is a member of the T-box
T-box
T-box refers to a group of transcription factors involved in limb and heart development. In humans and some other animals, defects in the TBX5 gene expression can lead to finger-like thumbs and ventricular septal defects in which there is no separation between the left and right ventricle of the...

family that encodes the transcription factor TBX20. Studies in mouse, human and fruitfly have shown that this gene is essential for early heart development
, adult heart function and yolk sac vasculature remodeling and has been associated with congenital heart diseases

. Tbx20 was also shown to be required for migration of hindbrain motor neurons and in facial neurons was proposed to be a positive regulator of the non-canonical Wnt signaling pathway.

Embryonic heart functions

Tbx20 knockout mouse embryos die at around or before E10.5 with hypoplastic hearts
.
This gene has been implicated in coordinating cardiac proliferation, regional specification
and formation of the cardiac chamber
.
Congenital heart diseases involving TBX20 include defects in septation, chamber growth and valvulogenesis
and increased Tbx20 expression was shown to cause congenital atrial septal defects, patent foramen ovale and cardiac valve defects.

Adult heart functions

In the fruitfly, knock-down of nmr (neuromancer), Drosophilas Tbx20 homolog gene, led to slower heart rate, arrythmyas and abnormal myofibrillar architecture.
Heterozygous Tbx20 knockout adult mice displayed left ventricle dilation, decreased wall thickness and contractile abnormalities.
Homozygous conditional cardiomyocyte Tbx20 knockout adult mice died within 15 days after knockout induction. Mice hearts presented with dilated cardiomyopathy and contraction-related dysfunctions such as abnormal atrioventricular conduction, slower heart rate, altered ventricular depolarization/repolarization and arrhythmias .

Known co-factors

Transcription factors GATA4 and NKX2-5 have been shown to physically interact with TBX20 and enhance gene expression.

Known downstream gene targets

Tbx2 was shown to be directly repressed by Tbx20 in the myocardium.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK