scholarly journals cDNA cloning and characterization of the protein encoded by RD, a gene located in the class III region of the human major histocompatibility complex

1993 ◽  
Vol 294 (2) ◽  
pp. 589-593 ◽  
Author(s):  
J Cheng ◽  
K J Macon ◽  
J E Volanakis

The RD gene, initially defined in the mouse, has been mapped between the Bf and C4A genes in the human major histocompatibility complex class III region. Using the mouse cDNA as a probe, we isolated and sequenced human RD cDNA clones. The composite nucleotide sequence consisted of 1301 nucleotides, excluding a poly(A) tail at the 3′ end. It contained a single open reading frame encoding a polypeptide of 380 amino acid residues with a calculated molecular mass of 42274 Da. The most striking structural feature of the deduced amino acid sequence is a region consisting entirely of 24 tandem repeats of an Arg-Asp (or Glu) dipeptide. The human RD cDNA was expressed in Escherichia coli as a fusion protein with glutathione S-transferase and used to produce antisera in rabbits. Western blot analysis and immunoprecipitation of lysates of biosynthetically labelled HeLa cells indicated that RD is a 44 kDa nuclear protein.

1993 ◽  
Vol 290 (3) ◽  
pp. 811-818 ◽  
Author(s):  
C M Milner ◽  
R D Campbell

The class III region of the human major histocompatibility complex spans approx. 1.1 Mbp on the short arm of chromosome 6 and is known to contain at least 36 genes. The complete nucleotide sequence of a 3.4 kb mRNA from one of these genes, G9a (or BAT8), has been determined from cDNA and genomic DNA clones. The single-copy G9a gene encodes a protein product of 1001 amino acids with a predicted molecular mass of 111,518 Da. The C-terminal region (residues 730-999) of the G9a protein has been expressed in Escherichia coli as a fusion protein with the 26 kDa glutathione S-transferase of Schistosoma japonicum (Sj26). The fusion protein has been used to raise antisera which, in Western-blot analysis, cross-react specifically with an intracellular protein of approx. 98 kDa. The function of the G9a protein is unknown. However, comparison of the derived amino acid sequence of G9a with the protein databases has revealed interesting similarities with a number of other proteins. The C-terminal region of G9a is 35% identical with a 149 amino acid segment of the Drosophila trithorax protein. In addition the G9a protein has been shown to contain six contiguous copies of a 33-amino acid repeat. This repeat, originally identified in the Notch protein of Drosophila and known as the cdc10/SW16 or ANK repeat, is also found in a number of other human proteins and may be involved in intracellular protein-protein interactions.


2014 ◽  
Vol 82 (5) ◽  
pp. 1939-1948 ◽  
Author(s):  
K. A. Elisa Kallio ◽  
Marja Marchesani ◽  
Efthymia Vlachopoulou ◽  
Päivi Mäntylä ◽  
Susanna Paju ◽  
...  

ABSTRACTPeriodontitis is a chronic inflammatory disease with a multifactorial etiology. We investigated whether human major histocompatibility complex (MHC) polymorphisms (6p21.3) are associated with periodontal parameters. Parogene 1 population samples (n= 169) were analyzed with 13,245 single nucleotide polymorphisms (SNPs) of the MHC region. Eighteen selected SNPs (P≤ 0.001) were replicated in Parogene 2 population samples (n= 339) and the Health 2000 Survey (n= 1,420). All subjects had a detailed clinical and radiographic oral health examination. Serum lymphotoxin-α (LTA) concentrations were measured in the Parogene populations, and the protein was detected in inflamed periodontal tissue. In the Parogene 1 population, 10 SNPs were associated with periodontal parameters. The strongest associations emerged from the parameters bleeding on probing (BOP) and a probing pocket depth (PPD) of ≥6 mm with the genesBAT1,NFKBIL1, andLTA. Six SNPs, rs11796, rs3130059, rs2239527, rs2071591, rs909253, and rs1041981 (r2, ≥0.92), constituted a risk haplotype. In the Parogene 1 population, the haplotype had the strongest association with the parameter BOP, a PPD of ≥6 mm, and severe periodontitis with odds ratios (95% confidence intervals) of 2.63 (2.21 to 3.20), 2.90 (2.37 to 3.52), and 3.10 (1.63 to 5.98), respectively. These results were replicated in the other two populations. High serum LTA concentrations in the Parogene population were associated with the periodontitis risk alleles of theLTASNPs (rs909253 and rs1041981) of the haplotype. In addition, the protein was expressed in inflamed gingival connective tissue. We identified a novelBAT1-NFKBIL1-LTAhaplotype as a significant contributor to the risk of periodontitis. The genetic polymorphisms in the MHC class III region may be functionally important in periodontitis susceptibility.


1991 ◽  
Vol 278 (3) ◽  
pp. 809-816 ◽  
Author(s):  
S L Hsieh ◽  
R D Campbell

At least 36 genes have now been located in a 680 kb segment of DNA between the class I and class II multigene families within the class III region of the human major histocompatibility complex on chromosome 6p21.3. The complete nucleotide sequence of the 4.3 kb mRNA of one of these genes, G7a (or BAT6), has been determined from cDNA and genomic clones. The single-copy G7a gene encodes a 1265-amino-acid protein of molecular mass 140,457 Da. Comparison of the derived amino acid sequence of the G7a protein with the National Biomedical Research Foundation protein databases revealed 42% identity in a 250-amino-acid overlap with Bacillus stearothermophilus valyl-tRNA synthetase, 38.0% identity in a 993-amino-acid overlap with Escherichia coli valyl-tRNA synthetase (val RS), and 48.3% identity in a 1043-amino-acid overlap with Saccharomyces cerevisiae valyl-tRNA synthetase. The protein sequence of G7a contains two short consensus sequences, His-Ile-Gly-His and Lys-Met-Ser-Lys-Ser, which is the typical signature structure of class I tRNA synthetases and indicative of the presence of the Rossman fold. In addition, the molecular mass of the G7a protein is the same as that of other mammalian valyl-tRNA synthetases. These features and the high sequence identity with yeast valyl-tRNA synthetase strongly support the fact that the G7a gene, located within the major histocompatibility complex, encodes the human valyl-tRNA synthetase.


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