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Protein Gene Polymorphisms (protein + gene_polymorphism)

Distribution by Scientific Domains
Life Sciences75%

Selected Abstracts

Prion protein gene polymorphisms in Saccharomyces cerevisiae

MOLECULAR MICROBIOLOGY, Issue 4 2003
Catarina G. Resende
Summary The yeast Saccharomyces cerevisiae genome encodes several proteins that, in laboratory strains, can take up a stable, transmissible prion form. In each case, this requires the Asn/Gln-rich prion-forming domain (PrD) of the protein to be intact. In order to further understand the evolutionary significance of this unusual property, we have examined four different prion genes and their corresponding PrDs, from a number of naturally occurring strains of S. cerevisiae. In 4 of the 16 strains studied we identified a new allele of the SUP35 gene (SUP35,19) that contains a 19-amino-acid deletion within the N-terminal PrD, a deletion that eliminates the prion property of Sup35p. In these strains a second prion gene, RNQ1, was found to be highly polymorphic, with eight different RNQ1 alleles detected in the six diploid strains studied. In contrast, for one other prion gene (URE2) and the sequence of the NEW1 gene encoding a PrD, no significant degree of DNA polymorphism was detected. Analysis of the naturally occurring alleles of RNQ1 and SUP35 indicated that the various polymorphisms identified were associated with DNA tandem repeats (6, 12, 33, 42 or 57 bp) within the coding sequences. The expansion and contraction of DNA repeats within the RNQ1 gene may provide an evolutionary mechanism that can ensure rapid change between the [PRION+] and [prion,] states. [source]

PRNP haplotype distribution in Moroccan goats

ANIMAL GENETICS, Issue 4 2009
C. Serrano
Summary Susceptibility/resistance to scrapie in sheep and goats is influenced by host prion protein gene (PRNP) genotype. In this study, we report the analysis of prion protein gene polymorphisms in 137 goats of two Moroccan populations: D'man and Chaouni. We found seven previously described amino acid polymorphisms at codons 37, 127, 137, 142, 154, 222 and 240, as well as three known silent mutations. In addition, we identified three new allelic variants: 101R and 139S in D'man goats and 145D in D'man and Chaouni individuals. The high frequency of the resistant allele 154H could offer genetic protection against the disease to the analysed animals. A total of 12 haplotypes and 28 genotypes were found, the distribution of which shows significant differences between both groups. Moreover, haplotype frequencies were compared with bibliographic data showing that the haplotype distribution of PRNP in Moroccan populations is genetically similar to Southern Italian and Greek goats. [source]

Prion protein gene polymorphisms in sheep in the state of Paraná, Brazil

ANIMAL GENETICS, Issue 6 2008
C. S. Sotomaior
Summary To determine the polymorphisms of the prion protein gene in sheep from the state of Paraná, Brazil, 323 animals of meat breeds (Suffolk, Hampshire Down, Texel, Ile de France, Dorper, Dorset, Santa Inês and crossbreds) were genotyped by restriction fragment length polymorphism (RFLP) analysis. The most frequent allele was ARQ, with a frequency of 0.61, followed by ARR (0.30). VRQ and AHQ alleles were present at very low frequencies (0.13 and 0.05 respectively), and the ARH allele was not found. Seven genotypes were identified (ARR/ARR, ARR/ARQ, ARQ/ARQ, ARR/VRQ, ARR/AHQ, ARQ/VRQ and ARQ/AHQ), of which ARQ/ARQ was the most frequent (0.41). The Santa Inês breed and crossbred animals showed the highest genotypic variability. [source]

The modifying effect of C-reactive protein gene polymorphisms on the association between central obesity and endometrial cancer risk

CANCER, Issue 11 2008
Wanqing Wen MD
Abstract BACKGROUND. Obesity is a major risk factor for endometrial cancer. Obesity, particularly central obesity, is considered as a systemic inflammatory condition and is related strongly to insulin resistance. C-reactive protein (CRP) is the most recognized biologic marker of chronic systematic inflammation, and it is conceivable that the CRP gene may work together with obesity in the development of endometrial cancer. METHODS. On the basis of a population-based case,control study in a Chinese population, the authors obtained obesity measurements and data on 6 CRP single-nucleotide polymorphisms (SNPs) from 1046 patients with newly diagnosed endometrial cancer (cases) and from 1035 age frequency-matched controls. The association of the CRP SNPs with endometrial cancer risk and their modification on the association between obesity and endometrial cancer risk were evaluated. RESULTS. Although CRP SNPs alone were not associated with endometrial cancer, the associations of endometrial cancer with central obesity, measured as the waist-to-hip ratio (WHR) and the waist circumference, seemed to be stronger in women who were homozygous for the major allele of reference SNP (rs)1130864 (cytidine [C]/C) than in women who had the C/thymidine (T) and T/T genotypes (interaction test: P = .013 for WHR; P = .083 for waist circumference). When the women were stratified further by menopausal status, the observed interactions persisted mainly in premenopausal women (interaction test: P < .001 for WHR; P = .002 for waist circumference). CONCLUSIONS. The current results suggested that, in the Chinese population that was studied, obesity-related insulin resistance and proinflammatory effects may play an important role in endometrial cancer risk, and these effects were modified significantly by the CRP SNP rs1130864. Cancer 2008. © 2008 American Cancer Society. [source]