GATA3 is a transcription factor that in humans is encoded by the GATA3 gene. Studies in animal models and humans indicate that it controls the expression of a wide range of biologically and clinically important genes. [5] [6] [7]
The GATA3 transcription factor is critical for the embryonic development of various tissues as well as for inflammatory and humoral immune responses and the proper functioning of the endothelium of blood vessels. GATA3 plays central role in allergy and immunity against worm infections. [8] [9] GATA3 haploinsufficiency (i.e. loss of one or the two inherited GATA3 genes) results in a congenital disorder termed the Barakat syndrome. [10] [11] [12]
Current clinical and laboratory research is focusing on determining the benefits of directly or indirectly blocking the action of GATA3 in inflammatory and allergic diseases such as asthma. [10] It is also proposed to be a clinically important marker for various types of cancer, particularly those of the breast. However, the role, if any, of GATA3 in the development of these cancers is under study and remains unclear. [13]
The GATA3 gene is located close to the end of the short arm of chromosome 10 at position p14. It consists of 8 exons, and codes for two variants viz., GATA3, variant 1, and GATA3, variant 2. [14] Expression of GATA3 may be regulated in part or at times by the antisense RNA, GATA3-AS1, whose gene is located close to the GATA3 gene on the short arm of chromosome 10 at position p14. [15] Various types of mutations including point mutations as well as small- and large-scale deletional mutations cause an autosomal dominant genetic disorder, the Barakat syndrome (also termed hypoparathyroidism, deafness, and renal dysplasia syndrome). The location of GATA3 borders that of other critical sites on chromosome 10, particularly a site located at 10p14-p13. Mutations in this site cause the congenital disorder DiGeorge syndrome/velocardiofacial syndrome complex 2 (or DiGeorge syndrome 2). [16] Large-scale deletions in GATA3 may span into the DiGeorge syndrome 2 area and thereby cause a complex syndrome with features of the Barakat syndrome combined with some of those of the DiGeorge syndrome 2. [12] [17] Knockout of both GATA3 genes in mice is fatal: these animals die at embryonic days 11 and 12 due to internal bleeding. They also exhibit gross deformities in the brain and spine as well as aberrations in fetal liver hematopoiesis. [18]
GATA3 variant 1 is a linear protein consisting of 444 amino acids. GATA3 variant 2 protein is an identically structured isoform of, but 1 amino acid shorter than, GATA3 variant 1. Differences, if any, in the functions of these two variants have not been reported. [19] With respect to the best studied variant, variant 1, but presumably also variant 2, one of the zinc finger structural motifs, ZNF2, is located at the protein's C-terminus and binds to specific gene promoter DNA sequences to regulate the expression of the genes controlled by these promoters. The other zinc finger, ZNF1, is at the protein's N-terminus and interacts with various nuclear factors, including Zinc finger protein 1 (i.e. ZFPM1, also termed Friends of GATA1 [i.e. FOG-1]) and ZFPM2 (i.e. FOG-2), that modulate GATA3's gene-stimulating actions. [20]
The GATA3 transcription factor regulates the expression of genes involved in the development of various tissues as well as genes involved in physiological as well as pathological humoral inflammatory and allergic responses. [12] [10]
GATA3 belongs to the GATA family of transcription factors. Gene-deletion studies in mice indicate that Gata3 (mouse gene equivalent to GATA3) is critical for the embryonic development and/or function of various cell types (e.g. fat cells, neural crest cells, lymphocytes) and tissues (e.g. kidney, liver, brain, spinal cord, mammary gland). [11] Studies in humans implicate GATA3 in the following:
Inactivating mutations in one of the two parental GATA3 genes cause the congenital disorder of hypoparathyroidism with sensorineural deafness and kidney malformations, i.e. the Barakat syndrome. This rare syndrome may occur in families or as a new mutation in an individual from a family with no history of the disorder. Mutations in GATA3 cause variable degrees of hypoparathyroidism, deafness, and kidney disease birth defects because of 1) individual differences in the penetrance of the mutation, 2) a sporadic, and as yet unexplained, association with malformation of uterus and vagina, and 3) mutations which extend beyond the GATA3 gene into chromosomal areas where mutations are responsible for developing other types of abnormalities which are characteristics of the DeGeorge syndrome 2. The Barakat syndrome is due to a haploinsufficiency in GATA3 levels, i.e. levels of the transcription factor that are insufficient for the normal development of the cited tissues during embryogenesis. [11] [12] [17]
Mouse studies indicate that inhibiting the expression of GATA3 using antisense RNA methods suppresses allergic inflammation. The protein is overexpressed in the afflicted tissues of individuals with various forms of allergy including asthma, rhinitis, nasal polyps, and atopic eczema. This suggests that it may have a role in promoting these disorders. [27] In a phase IIA clinical study of individuals suffering allergen-induced asthma, inhalation of Deoxyribozyme ST010, which specifically inactivates GATA3 messenger RNA, for 28 days reduced early and late immune lung responses to inhaled allergen. The clinical benefit of inhibiting GATA3 in this disorder is thought to be due to interfering with the function of Group 2 ILCs and Th2 cells by, for example, reducing their production of IL-4, IL-13, and especially IL-5. Reduction in these eosinophil-stimulating interleukins, it is postulated, reduces this cells ability to promote allergic reactivity and responses. [10] [28] For similar reasons, this treatment might also prove to be clinical useful for treating other allergic disorders. [27]
GATA3 is one of the three genes mutated in >10% of breast cancers (Cancer Genome Atlas). [29] Studies in mice indicate that the gene is critical for the normal development of breast tissue and directly regulates luminal cell (i.e. cells lining mammary ducts) differentiation in experimentally induced breast cancer. [18] [30] Analytic studies of human breast cancer tissues suggest that GATA3 is required for specific type of low risk breast cancer (i.e. luminal A), is integral to the expression of estrogen receptor alpha, and (in estrogen receptor negative/androgen receptor positive cancers) androgen receptor signaling. [31] [32] [33] These studies suggest that GATA3 is involved in the development of at least certain types of breast cancer in humans. However, there is disagreement on this, with some studies suggesting that the expression of the GATA3 acts to inhibit and other studies suggesting that it acts to promote the development, growth, and/or spread of this cancer. Further studies are needed to elucidate the role, if any, of GATA3 in the development of breast cancer. [18]
Immuocytochemical analysis of GATA3 protein in breast cells is a valuable marker for diagnosing primary breast cancer, being tested as positive in up to 94% of cases. It is especially valuable for estrogen receptor positive breast cancers but is less sensitive (435-66% elevated), although still more valuable than many other markers, for diagnosing triple-negative breast cancers. This analysis is widely used as a clinically valuable marker for breast cancer. [34] [35]
Similar to breast tumors, the role of GATA3 in the genesis of other tumor types is unclear but detection of its transcription factor product may be diagnostically useful. Immuocytochemical analysis of GATA3 protein is considered a valuable marker for certain types of urinary bladder and urethral cancers as well as for parathyroid gland tumors (cancerous or benign), Single series reports suggest that this analysis might also be of value for diagnosing salivary gland tumors, salivary duct carcinomas, mammary analog secretory carcinomas, benign ovarian Brenner tumors, benign Walthard cell rests, and paragangliomas. [36] [13]
GATA3 has been shown to interact with the following transcription factor regulators: ZFPM1 and ZFPM2; [20] LMO1; [37] [38] and FOXA1. [39] These regulators may promote or inhibit GATA3 in stimulating the expression of its target genes.
FOXP3, also known as scurfin, is a protein involved in immune system responses. A member of the FOX protein family, FOXP3 appears to function as a master regulator of the regulatory pathway in the development and function of regulatory T cells. Regulatory T cells generally turn the immune response down. In cancer, an excess of regulatory T cell activity can prevent the immune system from destroying cancer cells. In autoimmune disease, a deficiency of regulatory T cell activity can allow other autoimmune cells to attack the body's own tissues.
The interleukin 4 is a cytokine that induces differentiation of naive helper T cells (Th0 cells) to Th2 cells. Upon activation by IL-4, Th2 cells subsequently produce additional IL-4 in a positive feedback loop. IL-4 is produced primarily by mast cells, Th2 cells, eosinophils and basophils. It is closely related and has functions similar to IL-13.
Amphiregulin, also known as AREG, is a protein synthesized as a transmembrane glycoprotein with 252 aminoacids and it is encoded by the AREG gene. in humans.
Interleukin 5 (IL-5) is an interleukin produced by type-2 T helper cells and mast cells.
GATA-binding factor 1 or GATA-1 is the founding member of the GATA family of transcription factors. This protein is widely expressed throughout vertebrate species. In humans and mice, it is encoded by the GATA1 and Gata1 genes, respectively. These genes are located on the X chromosome in both species.
Mothers against decapentaplegic homolog 3 also known as SMAD family member 3 or SMAD3 is a protein that in humans is encoded by the SMAD3 gene.
Fibroblast growth factor receptor 2 (FGFR2) also known as CD332 is a protein that in humans is encoded by the FGFR2 gene residing on chromosome 10. FGFR2 is a receptor for fibroblast growth factor.
Fibroblast growth factor receptor 1 (FGFR1), also known as basic fibroblast growth factor receptor 1, fms-related tyrosine kinase-2 / Pfeiffer syndrome, and CD331, is a receptor tyrosine kinase whose ligands are specific members of the fibroblast growth factor family. FGFR1 has been shown to be associated with Pfeiffer syndrome, and clonal eosinophilias.
Signal transducer and activator of transcription 6 (STAT6) is a transcription factor that belongs to the Signal Transducer and Activator of Transcription (STAT) family of proteins. The proteins of STAT family transmit signals from a receptor complex to the nucleus and activate gene expression. Similarly as other STAT family proteins, STAT6 is also activated by growth factors and cytokines. STAT6 is mainly activated by cytokines interleukin-4 and interleukin-13.
GATA transcription factors are a family of transcription factors characterized by their ability to bind to the DNA sequence "GATA".
GATA2 or GATA-binding factor 2 is a transcription factor, i.e. a nuclear protein which regulates the expression of genes. It regulates many genes that are critical for the embryonic development, self-renewal, maintenance, and functionality of blood-forming, lympathic system-forming, and other tissue-forming stem cells. GATA2 is encoded by the GATA2 gene, a gene which often suffers germline and somatic mutations which lead to a wide range of familial and sporadic diseases, respectively. The gene and its product are targets for the treatment of these diseases.
T-box transcription factor TBX21, also called T-bet is a protein that in humans is encoded by the TBX21 gene. Though being for long thought of only as a master regulator of type 1 immune response, T-bet has recently been shown to be implicated in development of various immune cell subsets and maintenance of mucosal homeostasis.
Zinc finger and BTB domain-containing protein 32 is a protein that in humans is encoded by the 1960 bp ZBTB32 gene. The 52 kDa protein is a transcriptional repressor and the gene is expressed in T and B cells upon activation, but also significantly in testis cells. It is a member of the Poxviruses and Zinc-finger (POZ) and Krüppel (POK) family of proteins, and was identified in multiple screens involving either immune cell tumorigenesis or immune cell development.
"Basic helix-loop-helix family, member e41", or BHLHE41, is a gene that encodes a basic helix-loop-helix transcription factor repressor protein in various tissues of both humans and mice. It is also known as DEC2, hDEC2, and SHARP1, and was previously known as "basic helix-loop-helix domain containing, class B, 3", or BHLHB3. BHLHE41 is known for its role in the circadian molecular mechanisms that influence sleep quantity as well as its role in immune function and the maturation of T helper type 2 cell lineages associated with humoral immunity.
TOX high mobility group box family member 3, also known as TOX3, is a human gene.
Forkhead box protein A1 (FOXA1), also known as hepatocyte nuclear factor 3-alpha (HNF-3A), is a protein that in humans is encoded by the FOXA1 gene.
Interleukin 1 receptor-like 1, also known as IL1RL1 and ST2, is a protein that in humans is encoded by the IL1RL1 gene.
Clonal hypereosinophilia, also termed primary hypereosinophilia or clonal eosinophilia, is a grouping of hematological disorders all of which are characterized by the development and growth of a pre-malignant or malignant population of eosinophils, a type of white blood cell that occupies the bone marrow, blood, and other tissues. This population consists of a clone of eosinophils, i.e. a group of genetically identical eosinophils derived from a sufficiently mutated ancestor cell.
GATA2 deficiency is a grouping of several disorders caused by common defect, namely, familial or sporadic inactivating mutations in one of the two parental GATA2 genes. Being the gene haploinsufficient, mutations that cause a reduction in the cellular levels of the gene's product, GATA2, are autosomal dominant. The GATA2 protein is a transcription factor critical for the embryonic development, maintenance, and functionality of blood-forming, lymphatic-forming, and other tissue-forming stem cells. In consequence of these mutations, cellular levels of GATA2 are deficient and individuals develop over time hematological, immunological, lymphatic, or other presentations that may begin as apparently benign abnormalities but commonly progress to severe organ failure, opportunistic infections, virus infection-induced cancers, the myelodysplastic syndrome, and/or leukemia. GATA2 deficiency is a life-threatening and precancerous condition.
Steroid Receptor Associated and Regulated Protein (SRARP) in humans is a protein encoded by a gene of the same name with two exons that is located on chromosome 1p36.13. SRARP contains 169 amino acids and has a molecular weight of 17,657 Da.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.