NKX3-2
Description
The NKX3-2 (NK3 homeobox 2) is a protein-coding gene located on chromosome 4.
NKX3-2, also known as NKX3-2, is a human gene that is a homolog of the bagpipe (bap) gene in Drosophila, and is also known as Bapx1. The protein encoded by this gene is a homeodomain-containing transcription factor. NKX3-2 plays a role in the development of the axial and limb skeleton. Mutations disrupting the function of this gene are associated with spondylo-megaepiphyseal-metaphyseal dysplasia (SMMD). Nkx3-2 in mice also regulates patterning in the middle ear. Two small bones in the middle ear, the malleus and incus, are homologous to the articular and quadrate, the bones of the proximal jaw joint in fish and other non-mammalian jawed vertebrates. NKX3-2 expression is required to pattern the articulated joint between these jaw bones, as knockdowns or knockouts of this gene result in the loss of the jaw joint in zebrafish, chicken, and amphibians. Overexpression of this gene results in the development of ectopic mandibular cartilages in zebrafish and amphibians.
NKX3-2 acts as a transcriptional repressor, inhibiting the maturation of chondrocytes. It plays a vital role in the development of the distal stomach, ensuring proper antral-pyloric morphogenesis and the formation of antral-type epithelium. In collaboration with GSC, NKX3-2 defines the structural components of the middle ear, being essential for the development of the tympanic ring, gonium, and regulating the width of the malleus.
NKX3-2 is also known as BAPX1, NKX3.2, NKX3B, SMMD.
