pituitary homeobox 3; homeobox protein PITX3; paired-like homeodomain transcription factor 3 (PITX3, PTX3)

Function

• transcriptional regulator
• important for differentiation & maintenance of meso- diencephalic dopaminergic neurons during development
• also has roles in the long-term survival & maintenance of dopaminergic neurons
• activates NR4A2/NURR1- mediated transcription of genes such as SLC6A3, SLC18A2, TH & DRD2 which are essential for development of dopaminergic neurons
• acts by decreasing interaction of NR4A2/NURR1 with the corepressor NCOR2/SMRT which acts through histone deacetylases (HDACs) to keep promoters of NR4A2/NURR1 target genes in a repressed deacetylated state
• essential for the normal lens development & differentiation
• role in maintenance of mitotic activity of lens epithelial cells, fiber cell differentiation & in control of temporal & spatial activation of fiber cell-specific crystallins
• positively regulates FOXE3 expression & negatively regulates PROX1 in the anterior lens epithelium, preventing activation of CDKN1B/P27Kip1 & CDKN1C/P57Kip2 & thus maintains lens epithelial cells in cell cycle (putative)
• interacts with SFPQ (putative)

Structure

• belongs to the paired homeobox family, Bicoid subfamily
• contains 1 homeobox DNA-binding domain

Compartment

nucleus (putative)

Expression

• highly expressed in developing eye lens

Pathology

• defects in PITX3 are a cause of
  • cataract autosomal dominant
  • anterior segment mesenchymal dysgenesis
• defects in PITX3 are the cause of cataract posterior polar type 4

More general terms

• homeobox protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5309
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5309
• OMIM: https://mirror.omim.org/entry/107250
• OMIM: https://mirror.omim.org/entry/602669
• OMIM: https://mirror.omim.org/entry/604219
• OMIM: https://mirror.omim.org/entry/610623
• UniProt: http://www.uniprot.org/uniprot/O75364.html