Disease relevance of TRGC1

• Gross alterations in the C1 inhibitor gene account for about 20% of the hereditary angioedema chromosomes and consequently make this gene a prime example of the mutagenic liability of Alu repeats [1].
• The interaction of a subset of these polypeptides with alpha TIF is stimulated by post-translational modifications of the C1 proteins, suggesting that this factor may be a critical target for the regulation of the herpes simplex virus alpha/IE transcription [2].
• Increase in sensitivity to soluble CD4 by primary HIV type 1 isolates after passage through C8166 cells: association with sequence differences in the first constant (C1) region of glycoprotein 120 [3].
• The authors report a new technique for C-1 laminoplasty without fusion in the treatment of cervical myelopathy associated with a retroodontoid pseudotumor (also known as a phantom tumor) [4].

High impact information on TRGC1

• Heterozygosity for a mutant dysfunctional C1 inhibitor protein, a member of the serine proteinase inhibitor (serpin) superfamily, results in type II hereditary angioneurotic oedema [5].
• Mutation of a conserved sequence in the C1 promoter abolishes both ABA regulation and VP1 trans-activation [6].
• The Viviparous-1 gene and abscisic acid activate the C1 regulatory gene for anthocyanin biosynthesis during seed maturation in maize [6].
• We show that VP1 overexpression and the hormone, abscisic acid (ABA), activate a reporter gene driven by the C1 promoter in maize protoplasts [6].
• A complete mutational scan of the gene coding for the serpin C1 inhibitor, comprising all eight exons and adjacent intron sequences and 550 bp preceding the transcription start site, was rapidly accomplished in 36 unrelated angioedema patients by using fluorescence-assisted mismatch analysis (FAMA) [7].

Biological context of TRGC1

• The constant gamma 1 gene, TRGC1, consists of three exons, whereas the TRGC2 gene contains four or five exons due to the duplication or triplication of exon 2 and spans 9.5 kb or 12 kb, respectively [8].
• Exon duplication and triplication in the human T-cell receptor gamma constant region genes and RFLP in French, Lebanese, Tunisian, and black African populations [8].
• We propose a model involving unequal crossing-overs to explain the organization and the evolution of the TRGC locus [8].
• The availability of genomic clones representative of the T-cell receptor constant gamma (TRGC) ovine genes enabled us to demonstrate, by fluorescent in situ hybridization (FISH) on cattle and sheep metaphases, the presence of two T-cell receptor gamma (TRG1@ and TRG2@) paralogous loci separated by at least five chromosomal bands on chromosome 4 [9].
• The only differences that sorted with biological phenotype were in the first constant (C1) region of gp120 [3].

Anatomical context of TRGC1

• In the human T cell receptor gamma (TRG) locus, fourteen variable (TRGV) genes belonging to four subgroups have been identified upstream of two constant region (TRGC) genes [10].
• In vitro rabbit reticulocyte lysate and in vivo Xenopus oocyte translation systems both produce from a single mRNA two discrete polypeptide species that accumulate in a ratio similar to that of mammalian C1 and C2 proteins in vivo [11].
• Rapid and sensitive techniques for identification and analysis of 'reactive-centre' mutants of C1-inhibitor proteins contained in type II hereditary angio-oedema plasmas [12].
• Hypoglossal nerve palsy after posterior screw placement on the C-1 lateral mass. Case report [13].
• It usually moves with the clivus or the anterior arch of C-1 (dystopic) or rarely with the dens (orthotopic) [14].

Associations of TRGC1 with chemical compounds

• We suggest that VP1 activates C1 specifically during maturation by interacting with one or more ABA-regulated transcription factors [6].
• The P1 residue of C1 inhibitor is arginine and hence a potential cleavage site for trypsin [12].
• The C10 group showed lower c-fos expression in the LC than that of rats in the S and C1 groups (P < 0.05) [15].
• The authors review the cases of three patients who underwent C-1 laminoplasty in which hydroxyapatite was used and fusion was not performed [4].
• U18666A is known to inhibit Niemann-Pick C1 protein-dependent vesicular transport of cholesterol from endosomal compartments to the trans-Golgi network and the plasma membrane [16].

Analytical, diagnostic and therapeutic context of TRGC1

• Southern blot hybridization confirmed the presence of at least two TCRGC genes and indicated that the vast majority of horse alpha beta T cells rearrange either one or both TCRG alleles [17].
• METHODS: Thirty-six rats were divided into 6 groups as follows: formalin test + saline (FS); formalin test + clonidine (1 mg.kg(-1)) (FC1); formalin test + clonidine (10 mg.kg(-1)) (FC10); saline (S); clonidine (1 mg.kg(-1)) (C1); and clonidine (10 mg.kg(-1)) (C10) [15].

References