Paired box protein Pax-7 is a protein that in humans is encoded by the PAX7 gene. [5] [6] [7]
Paired box protein Pax-7 is a protein that in humans is encoded by the PAX7 gene. [5] [6] [7]
Pax-7 plays a role in neural crest development and gastrulation, and it is an important factor in the expression of neural crest markers such as Slug, Sox9, Sox10 and HNK-1. [8] PAX7 is expressed in the palatal shelf of the maxilla, Meckel's cartilage, mesencephalon, nasal cavity, nasal epithelium, nasal capsule and pons.
Pax7 is a transcription factor that plays a role in myogenesis through regulation of muscle precursor cells proliferation. It can bind to DNA as an heterodimer with PAX3. Also interacts with PAXBP1; the interaction links PAX7 to a WDR5-containing histone methyltransferase complex By similarity. Interacts with DAXX too. [9]
PAX7 functions as a marker for a rare subset of spermatogonial stem cells, specifically a sub set of Asingle spermatogonia. [10] These PAX7+ spermatogonia are rare in adult testis but are much more prevalent in newborns, making up 28% of germ cells in neonate testis. [10] Unlike PAX7+ muscle satellite cells, PAX7+ spermatogonia rapidly proliferate and are not quiescent. [10] [11] PAX7+ spermatogonia are able to give rise to all stages of spermatogenesis and produce motile sperm. [10] However, PAX7 is not required for spermatogenesis, as mice without PAX7+ spermatogonia show no deficits in fertility. [10]
PAX7 may also function in the recovery in spermatogenesis. Unlike other spermatogonia, PAX7+ spermatogonia are resistant to radiation and chemotherapy. [10] The surviving PAX7+ spermatogonia are able to increase in number following these therapies and differentiate into the other forms of spermatogonia that did not survive. [10] Additionally, mice lacking PAX7 had delayed recovery of spermatogenesis following exposure to busulfan when compared to control mice. [10]
Pax proteins play critical roles during fetal development and cancer growth. The specific function of the paired box gene 7 is unknown but speculated to involve tumor suppression since fusion of this gene with a forkhead domain family member has been associated with alveolar rhabdomyosarcoma. Alternative splicing in this gene has produced two known products but the biological significance of the variants is unknown. [7] Animal studies show that mutant mice have malformation of maxilla and the nose. [12]
Rhabdomyosarcoma (RMS) is a highly aggressive form of cancer that develops from mesenchymal cells that have failed to fully differentiate into myocytes of skeletal muscle. Cells of the tumor are identified as rhabdomyoblasts.
In evolutionary developmental biology, Paired box (Pax) genes are a family of genes coding for tissue specific transcription factors containing an N-terminal paired domain and usually a partial, or in the case of four family members, a complete homeodomain to the C-terminus. An octapeptide as well as a Pro-Ser-Thr-rich C terminus may also be present. Pax proteins are important in early animal development for the specification of specific tissues, as well as during epimorphic limb regeneration in animals capable of such.
Paired box protein Pax-6, also known as aniridia type II protein (AN2) or oculorhombin, is a protein that in humans is encoded by the PAX6 gene.
The PAX3 gene encodes a member of the paired box or PAX family of transcription factors. The PAX family consists of nine human (PAX1-PAX9) and nine mouse (Pax1-Pax9) members arranged into four subfamilies. Human PAX3 and mouse Pax3 are present in a subfamily along with the highly homologous human PAX7 and mouse Pax7 genes. The human PAX3 gene is located in the 2q36.1 chromosomal region, and contains 10 exons within a 100 kb region.
Alveolar rhabdomyosarcoma (ARMS) is a subtype of the rhabdomyosarcoma soft tissue cancer family whose lineage is from mesenchymal cells and are related to skeletal muscle cells. ARMS tumors resemble the alveolar tissue in the lungs. Tumor location varies from patient to patient, but is commonly found in the head and neck region, male and female urogenital tracts, the torso, and extremities. Two fusion proteins can be associated with ARMS, but are not necessary, PAX3-FKHR. and PAX7-FKHR. In children and adolescents ARMS accounts for about 1 percent of all malignancies, has an incidence rate of 1 per million, and most cases occur sporadically with no genetic predisposition. PAX3-FOXO1 is now known to drive cancer-promoting gene expression programs through creation of distant genetic elements called super enhancers.
SRY -box 2, also known as SOX2, is a transcription factor that is essential for maintaining self-renewal, or pluripotency, of undifferentiated embryonic stem cells. Sox2 has a critical role in maintenance of embryonic and neural stem cells.
Paired box gene 8, also known as PAX8, is a protein which in humans is encoded by the PAX8 gene.
Paired box protein Pax-5 is a protein that in humans is encoded by the PAX5 gene.
Deleted in azoospermia 1, also known as DAZ1, is a protein which in humans is encoded by the DAZ1 gene.
Calcium and integrin-binding protein 1 is a protein that in humans is encoded by the CIB1 gene and is located in Chromosome 15. The protein encoded by this gene is a member of the calcium-binding protein family. The specific function of this protein has not yet been determined; however this protein is known to interact with DNA-dependent protein kinase and may play a role in kinase-phosphatase regulation of DNA end-joining. This protein also interacts with integrin alpha(IIb)beta(3), which may implicate this protein as a regulatory molecule for alpha(IIb)beta(3).
Paired box gene 4, also known as PAX4, is a protein which in humans is encoded by the PAX4 gene.
Paired box gene 9, also known as PAX9, is a protein which in humans is encoded by the PAX9 gene. It is also found in other mammals.
Transcription factor SOX-3 is a protein that in humans is encoded by the SOX3 gene. This gene encodes a member of the SOX family of transcription factors involved in the regulation of embryonic brain development and in determination of cell fate. The encoded protein acts as a transcriptional activator.
Deleted in azoospermia protein 2 is a protein that in humans is encoded by the DAZ2 gene.
Paired box protein Pax-1 is a protein that in humans is encoded by the PAX1 gene.
Homeobox protein engrailed-1 is a protein that in humans is encoded by the EN1 gene.
Transcription factor AP-2 beta also known as AP2-beta is a protein that in humans is encoded by the TFAP2B gene.
Forkhead box protein O1 (FOXO1), also known as forkhead in rhabdomyosarcoma (FKHR), is a protein that in humans is encoded by the FOXO1 gene. FOXO1 is a transcription factor that plays important roles in regulation of gluconeogenesis and glycogenolysis by insulin signaling, and is also central to the decision for a preadipocyte to commit to adipogenesis. It is primarily regulated through phosphorylation on multiple residues; its transcriptional activity is dependent on its phosphorylation state.
SOX1 is a gene that encodes a transcription factor with a HMG-box DNA-binding domain and functions primarily in neurogenesis. SOX1, SOX2 and SOX3, members of the SOX gene family, contain transcription factors related to SRY, the testis-determining factor.
A spermatogonial stem cell (SSC), also known as a type A spermatogonium, is a spermatogonium that does not differentiate into a spermatocyte, a precursor of sperm cells. Instead, they continue dividing into other spermatogonia or remain dormant to maintain a reserve of spermatogonia. Type B spermatogonia, on the other hand, differentiate into spermatocytes, which in turn undergo meiosis to eventually form mature sperm cells.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.