Recombinant Human Forkhead box protein C1 (FOXC1)

Function

DNA-binding transcriptional factor that plays a role in a broad range of cellular and developmental processes such as eye, bones, cardiovascular, kidney and skin development (PubMed:11782474, PubMed:14506133, PubMed:14578375, PubMed:15277473, PubMed:15299087, PubMed:15684392, PubMed:16449236, PubMed:16492674, PubMed:17210863, PubMed:19279310, PubMed:19793056, PubMed:25786029, PubMed:27804176, PubMed:27907090). Acts either as a transcriptional activator or repressor (PubMed:11782474). Binds to the consensus binding site 5'-[G/C][A/T]AAA[T/C]AA[A/C]-3' in promoter of target genes (PubMed:11782474, PubMed:12533514, PubMed:14506133, PubMed:19793056, PubMed:27804176, PubMed:7957066). Upon DNA-binding, promotes DNA bending (PubMed:14506133, PubMed:7957066). Acts as a transcriptional coactivator (PubMed:26565916). Stimulates Indian hedgehog (Ihh)-induced target gene expression mediated by the transcription factor GLI2, and hence regulates endochondral ossification (By similarity). Also acts as a transcriptional coregulator by increasing DNA-binding capacity of GLI2 in breast cancer cells (PubMed:26565916). Regulates FOXO1 through binding to a conserved element, 5'-GTAAACAAA-3' in its promoter region, implicating FOXC1 as an important regulator of cell viability and resistance to oxidative stress in the eye (PubMed:17993506). Cooperates with transcription factor FOXC2 in regulating expression of genes that maintain podocyte integrity (By similarity). Promotes cell growth inhibition by stopping the cell cycle in the G1 phase through TGFB1-mediated signals (PubMed:12408963). Involved in epithelial-mesenchymal transition (EMT) induction by increasing cell proliferation, migration and invasion (PubMed:20406990, PubMed:22991501). Involved in chemokine CXCL12-induced endothelial cell migration through the control of CXCR4 expression (By similarity). Plays a role in the gene regulatory network essential for epidermal keratinocyte terminal differentiation (PubMed:27907090). Essential developmental transcriptional factor required for mesoderm-derived tissues, such as the somites, skin, bone and cartilage. Positively regulates CXCL12 and stem cell factor expression in bone marrow mesenchymal progenitor cells, and hence plays a role in the development and maintenance of mesenchymal niches for haematopoietic stem and progenitor cells (HSPC). Plays a role in corneal transparency by preventing both blood vessel and lymphatic vessel growth during embryonic development in a VEGF-dependent manner. Involved in chemokine CXCL12-induced endothelial cell migration through the control of CXCR4 expression (By similarity). May function as a tumor suppressor (PubMed:12408963)

Subcellular Location

Nucleus

Disease Association

Axenfeld-Rieger syndrome 3 (RIEG3) : An autosomal dominant disorder of morphogenesis that results in abnormal development of the anterior segment of the eye, and results in blindness from glaucoma in approximately 50% of affected individuals. Features include posterior corneal embryotoxon, prominent Schwalbe line and iris adhesion to the Schwalbe line, hypertelorism, hypodontia, sensorineural deafness, redundant periumbilical skin, and cardiovascular defects such as patent ductus arteriosus and atrial septal defect. When associated with tooth anomalies, the disorder is known as Rieger syndrome. [The disease is caused by variants affecting the gene represented in this entry] | Anterior segment dysgenesis 3 (ASGD3) : A form of anterior segment dysgenesis, a group of defects affecting anterior structures of the eye including cornea, iris, lens, trabecular meshwork, and Schlemm canal. Anterior segment dysgeneses result from abnormal migration or differentiation of the neural crest derived mesenchymal cells that give rise to components of the anterior chamber during eye development. Different anterior segment anomalies may exist alone or in combination, including iris hypoplasia, enlarged or reduced corneal diameter, corneal vascularization and opacity, posterior embryotoxon, corectopia, polycoria, abnormal iridocorneal angle, ectopia lentis, and anterior synechiae between the iris and posterior corneal surface. Clinical conditions falling within the phenotypic spectrum of anterior segment dysgeneses include aniridia, Axenfeld anomaly, Reiger anomaly/syndrome, Peters anomaly, and iridogoniodysgenesis. ASGD3 inheritance is autosomal dominant. [The disease is caused by variants affecting the gene represented in this entry]

Tissue Specificity

Expressed in keratinocytes of epidermis and hair follicle (PubMed:27907090). Expressed strongly in microvascular invasion (MVI) formation, basal-like breast cancer (BLBC) and hepatocellular tumors (PubMed:20406990, PubMed:22991501). Expressed in breast cancers (at protein level) (PubMed:26565916). Expressed in hematopoietic cells (PubMed:8499623)

Subunit

Monomer. Interacts with C1QBP (PubMed:18676636). Interacts (via N-terminus) with GLI2 (via C-terminal internal region); this interaction is direct and increases GLI2 DNA-binding and transcriptional activity through a smoothened (SMO)-independent Hedgehog (Hh) signaling pathway (PubMed:26565916). Interacts (via C-terminus domain) with PITX2 isoform 3 (via homeobox domain) (PubMed:16449236). Interacts with FLNA and PBX1 (PubMed:15684392)

• Nishimura D.Y. et al. The forkhead transcription factor gene FKHL7 is responsible for glaucoma phenotypes which map to 6p25. — Nat. Genet. (1998)
• Mears A.J. et al. Mutations of the forkhead/winged-helix gene, FKHL7, in patients with Axenfeld-Rieger anomaly. — Am. J. Hum. Genet. (1998)
• Komatireddy S. et al. Mutation spectrum of FOXC1 and clinical genetic heterogeneity of Axenfeld-Rieger anomaly in India. — Mol. Vis. (2003)
• Mungall A.J. et al. The DNA sequence and analysis of human chromosome 6. — Nature (2003)
• Hromas R. et al. Drosophila forkhead homologues are expressed in a lineage-restricted manner in human hematopoietic cells. — Blood (1993)
• Pierrou S. et al. Cloning and characterization of seven human forkhead proteins: binding site specificity and DNA bending. — EMBO J. (1994)
• Zhou Y. et al. Identification of FOXC1 as a TGF-beta1 responsive gene and its involvement in negative regulation of cell growth. — Genomics (2002)
• Berry F.B. et al. FOXC1 transcriptional regulation is mediated by N- and C-terminal activation domains and contains a phosphorylated transcriptional inhibitory domain. — J. Biol. Chem. (2002)