Early growth response protein 2 is a protein that in humans is encoded by the EGR2 gene. EGR2 (also termed Krox20) is a transcription regulatory factor, containing three zinc finger DNA-binding sites, and is highly expressed in a population of migrating neural crest cells. [5] [6] [7] It is later expressed in the neural crest derived cells of the cranial ganglion. The protein encoded by Krox20 contains two cys2his2-type zinc fingers. Krox20 gene expression is restricted to the early hindbrain development. [6] [8] It is evolutionarily conserved in vertebrates, humans, mice, chicks, and zebra fish. [9] In addition, the amino acid sequence and most aspects of the embryonic gene pattern is conserved among vertebrates, further implicating its role in hindbrain development. [7] [10] [11] [12] When the Krox20 is deleted in mice, the protein coding ability of the Krox20 gene (including the DNA-binding domain of the zinc finger) is diminished. These mice are unable to survive after birth and exhibit major hindbrain defects. [6] [8] These defects include but are not limited to defects in formation of cranial sensory ganglia, partial fusion of the trigeminal nerve (V) with the facial (VII) and auditory (VII) nerves, the proximal nerve roots coming off of these ganglia were disorganized and intertwined among one another as they entered the brainstem, and there was fusion of the glossopharyngeal (IX) nerve complex. [13] [14] [15]
The early growth response protein 2 is a transcription factor with three tandem C2H2-type zinc fingers. Mutations in this gene are associated with the autosomal dominant Charcot-Marie-Tooth disease, type 1D, [16] Dejerine–Sottas disease, [17] and Congenital Hypomyelinating Neuropathy. [18] Two studies have linked EGR2 expression to proliferation of osteoprogenitors [19] and cell lines derived from Ewing sarcoma, which is a highly aggressive bone-associated cancer. [20]
New research suggests that Krox20 - or the lack of it - is the reason for male baldness. [21]
Charcot–Marie–Tooth disease (CMT) is a hereditary motor and sensory neuropathy of the peripheral nervous system characterized by progressive loss of muscle tissue and touch sensation across various parts of the body. This disease is the most commonly inherited neurological disorder, affecting about one in 2,500 people. It is named after those who classically described it: the Frenchman Jean-Martin Charcot (1825–1893), his pupil Pierre Marie (1853–1940), and the Briton Howard Henry Tooth (1856–1925).
Schwann cells or neurolemmocytes are the principal glia of the peripheral nervous system (PNS). Glial cells function to support neurons and in the PNS, also include satellite cells, olfactory ensheathing cells, enteric glia and glia that reside at sensory nerve endings, such as the Pacinian corpuscle. The two types of Schwann cells are myelinating and nonmyelinating. Myelinating Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. The Schwann cell promoter is present in the downstream region of the human dystrophin gene that gives shortened transcript that are again synthesized in a tissue-specific manner.
EGR-1 also known as ZNF268 or NGFI-A is a protein that in humans is encoded by the EGR1 gene.
Dejerine–Sottas disease, also known as, Dejerine–Sottas neuropathy, progressive hypertrophic interstitial polyneuropathy of childhood and onion bulb neuropathy, is a hereditary neurological disorder characterised by damage to the peripheral nerves and resulting progressive muscle wasting. The condition is caused by mutations in a various genes and currently has no known cure.
Myelin protein zero is a single membrane glycoprotein which in humans is encoded by the MPZ gene. P0 is a major structural component of the myelin sheath in the peripheral nervous system (PNS). Myelin protein zero is expressed by Schwann cells and accounts for over 50% of all proteins in the peripheral nervous system, making it the most common protein expressed in the PNS. Mutations in myelin protein zero can cause myelin deficiency and are associated with neuropathies like Charcot–Marie–Tooth disease and Dejerine–Sottas disease.
Growth arrest-specific protein 3 (GAS-3), also called peripheral myelin protein 22 (PMP22), is a protein which in humans is encoded by the PMP22 gene.
Transcription factor SOX-10 is a protein that in humans is encoded by the SOX10 gene.
Homeobox protein Hox-A1 is a protein that in humans is encoded by the HOXA1 gene.
Homeobox protein Hox-B2 is a protein that in humans is encoded by the HOXB2 gene.
Lipopolysaccharide-induced tumor necrosis factor-alpha factor is a protein that in humans is encoded by the LITAF gene.
Ganglioside-induced differentiation-associated protein 1 is a type of protein that in humans is encoded by the GDAP1 gene.
Homeobox protein Hox-A3 is a protein that in humans is encoded by the HOXA3 gene.
Periaxin is a protein that in humans is encoded by the PRX gene.
NGFI-A-binding protein 2 also known as EGR-1-binding protein 2 or melanoma-associated delayed early response protein (MADER) is a protein that in humans is encoded by the NAB2 gene.
Early growth response protein 3 is a protein in humans, encoded by the EGR3 gene.
NGFI-A-binding protein 1 is a protein that in humans is encoded by the NAB1 gene.
Zinc finger and BTB domain-containing protein 7B is a protein that in humans is encoded by the ZBTB7B gene. ZFP67 is an early growth response gene that encodes a zinc finger-containing transcription factor that binds to the promoter regions of type I collagen genes and has a role in development.[supplied by OMIM]
Polyphosphoinositide phosphatase also known as phosphatidylinositol 3,5-bisphosphate 5-phosphatase or SAC domain-containing protein 3 (Sac3) is an enzyme that in humans is encoded by the FIG4 gene. Fig4 is an abbreviation for Factor-Induced Gene.
Early growth response protein 4 (EGR-4), also known as AT133, is a protein that in humans is encoded by the EGR4 gene.
Patrick Charnay is a French biologist, researcher. Serving as an Emeritus research director for Inserm, he works and teaches in molecular genetics and development biology at the École normale supérieure (ENS) in Paris.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.