| Modification Notes |
Nkx homeodomain proteins are members of a large family of vertebrate transcription factors that have a strong homology to the NK genes in Drosophila. Nkx proteins are involved in several aspects of cell type specification and maintenance of differentiated tissue functions. Nkx-2.3 contains a homeobox, a conserved NK2 domain, a C-terminal GIRAW motif and an N-terminal homology domain that is conserved among all NK2 genes. Expression of Nkx-2.3 is activated later in differentiated myocardial cells, and the protein is primarily detected in gut mesoderm, distinct regions of the brachial arches, the tongue epithelium and some domains in the developing jaws. Nkx-2.3 is necessary to function as a transcriptional activator during the earliest stages of heart formation. Overexpression of Nkx-2.3 leads to an enlarged heart due to a thickening of the myocardium caused by an increase in the overall number of myocardial cells. |