Nuclear factor 1 B-type is a protein that in humans is encoded by the NFIB gene. [5] [6]
NFIB haploinsufficiency is also associated with intellectual disability and macrocephaly, as are NFIA and NFIX. [7]
The NFIB gene is a part of the NFI gene complex that includes three other genes (NFIA, NFIC and NFIX). [8] [9] The NFIB gene is a protein coding gene that also serves as a transcription factor. [10] This gene is essential in embryonic development and it works together with its gene complex to initiate tissue differentiation in the fetus. NFIB has the highest concentrations in the lung, skeletal muscle and heart but is also found in the areas of the developing liver, kidneys and brain. [8]
Through knockout experiments, researchers found that mice without the NFIB gene have severely underdeveloped lungs. [9] [11] This mutation does not seem to cause spontaneous abortions because in utero the fetus does not use its lungs for respiration. However, this becomes lethal once the fetus is born and has to take its first breath. It is thought that NFIB plays a role in down regulating the transcription factors TGF-β1 and Shh in normal gestation because they remained high in knockout experiments. [9] The absence of NFIB also leads to insufficient amounts of surfactant being produced which is one reason why the mice cannot breathe once it is born. [9] The knockout experiments demonstrated that NFIB has a significant role in fore-brain development. NFIB is typically found in pontine nuclei of the CNS, the cerebral cortex and the white matter of the brain and without NFIB these areas are dramatically affected. [8] [11]
Absence of one copy is associated with macrocephaly and intellectual disability. This associated was confirmed in mouse modelswhere deletion of one copy resulted in enlargement of the brain while preserving its overall organisation.
Nuclear factor erythroid 2-related factor 2 (NRF2), also known as nuclear factor erythroid-derived 2-like 2, is a transcription factor that in humans is encoded by the NFE2L2 gene. NRF2 is a basic leucine zipper (bZIP) protein that may regulate the expression of antioxidant proteins that protect against oxidative damage triggered by injury and inflammation, according to preliminary research. In vitro, NRF2 binds to antioxidant response elements (AREs) in the promoter regions of genes encoding cytoprotective proteins. NRF2 induces the expression of heme oxygenase 1 in vitro leading to an increase in phase II enzymes. NRF2 also inhibits the NLRP3 inflammasome.
NK2 homeobox 1 (NKX2-1), also known as thyroid transcription factor 1 (TTF-1), is a protein which in humans is encoded by the NKX2-1 gene.
Glutaredoxin-1 is a protein that in humans is encoded by the GLRX gene.
Hepatoma-derived growth factor (HDGF) also known as high mobility group protein 1-like 2 (HMG-1L2) is a protein that in humans is encoded by the HDGF gene.
Homeobox protein Hox-B3 is a protein that in humans is encoded by the HOXB3 gene.
Nuclear factor 1 C-type is a protein that in humans is encoded by the NFIC gene.
Nuclear factor 1 A-type is a protein that in humans is encoded by the NFIA gene.
Nuclear factor 1 X-type is a protein that in humans is encoded by the NFIX gene. NFI-X3, a splice variant of NFIX, regulates Glial fibrillary acidic protein and YKL-40 in astrocytes.
Transcription factor TFIIIB component B″ homolog also known as TFIIIB150 is a protein that in humans is encoded by the BDP1 gene.
Zinc finger protein ZFPM2, i.e. zinc finger protein, FOG family member 2, but also termed Friend of GATA2, Friend of GATA-2, FOG2, or FOG-2, is a protein that in humans is encoded by the ZFPM2 and in mice by the Zfpm2 gene.
Eukaryotic translation initiation factor 4E transporter is a protein that in humans is encoded by the EIF4ENIF1 gene.
Chromodomain-helicase-DNA-binding protein 8 is an enzyme that in humans is encoded by the CHD8 gene.
B-cell lymphoma/leukemia 11B is a protein that in humans is encoded by the BCL11B gene.
Aryl hydrocarbon receptor nuclear translocator 2 is a protein that in humans is encoded by the ARNT2 gene.
Transcription factor SOX-8 is a protein that in humans is encoded by the SOX8 gene.
Transcription factor AP-4 , also known as TFAP4, is a protein which in humans is encoded by the TFAP4 gene.
Zinc finger protein 143 is a protein that in humans is encoded by the ZNF143 gene.
Zinc finger protein 267 is a protein that in humans is encoded by the ZNF267 gene.
Importin-13 is a protein encoded by the IPO13 gene in humans. Importin-13 is a member of the importin-β family of nuclear transport receptors (NTRs) and was first identified as a transport receptor in 2000. According to PSI-blast based secondary structure PREDiction (PSIPRED), importin-13 contains 38 α-helices. Importin-13 accommodates a range of cargoes due to its flexible superhelical structure and a cargo binding and release system that is distinct from other importin-like transport receptors. IPO13 is broadly expressed in a variety of tissues in the human body, including the heart, cornea, fetal lung, brain, endometrial carcinoma, and testes.
Forkhead box protein A2 (FOXA2), also known as hepatocyte nuclear factor 3-beta (HNF-3B), is a transcription factor that plays an important role during development, in mature tissues and, when dysregulated or mutated, also in cancer.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.