HLA gene and haplotype frequencies in a Nagaybaks population from the Chelyabinsk Region (Russian South Urals)

A total of 112 Nagaybaks, a Turkic ethnoconfessional group living mainly in the Nagaybak district of the Chelyabinsk Region of Russian South Urals, were genotyped for HLA-A, -B, -DRB1, -DQA1 and -DQB1 loci using PCR-SSP (low-resolution) and HLA-A29 (high-resolution). All loci were in Hardy-Weinberg equilibrium (all p values >0.1 thus showing no locus-level deviations. The genotype data are available in the Allele Frequencies Net Database under the population name ‘‘Russia, South Ural, Chelyabinsk Region, Nagaybaks” and the identifier AFND0003397.     

The in situ spatial arrangement of the influenza A virus matrix protein M1 assessed by tritium bombardment.

Intact influenza A virions were bombarded with thermally activated tritium atoms, and the intramolecular distribution of the label in the matrix protein M1 was analyzed to determine the in situ accessibility of its tryptic fragments. These data were combined with the previously reported x-ray crystal structure of the M1 fragment 2-158 [Sha, B. & Luo, M. (1997) Nat. Struct. Biol. 4, 239-244] and the predicted topology of the C domain (159-252) to propose a model of M1 arrangement in the virus particle.     

Liquid-liquid separation in solutions of normal and sickle cell hemoglobin

We show that in solutions of human hemoglobin (Hb)--oxy- and deoxy-Hb A or S--of near-physiological pH, ionic strength, and Hb concentration, liquid-liquid phase separation occurs reversibly and reproducibly at temperatures between 35 and 40 degrees C. In solutions of deoxy-HbS, we demonstrate that the dense liquid droplets facilitate the nucleation of HbS polymers, whose formation is the primary pathogenic event for sickle cell anemia. In view of recent results that shifts of the liquid-liquid separation phase boundary can be achieved by nontoxic additives at molar concentrations up to 30 times lower than the protein concentrations, these findings open new avenues for the inhibition of the HbS polymerization.     

BRCA2 BRC motifs bind RAD51-DNA filaments

Germ-line mutations in BRCA2 account for approximately half the cases of autosomal dominant familial breast cancers. BRCA2 has been shown to interact directly with RAD51, an essential component of the cellular machinery for homologous recombination and the maintenance of genome stability. Interactions between BRCA2 and RAD51 take place by means of the conserved BRC repeat regions of BRCA2. Previously, it was shown that peptides corresponding to BRC3 or BRC4 bind RAD51 monomers and block RAD51-DNA filament formation. In this work, we further analyze these interactions and find that at lower molar ratios BRC3 or BRC4 actually bind and form stable complexes with RAD51-DNA nucleoprotein filaments. Only at high concentrations of the BRC repeats are filaments disrupted. The specific protein-protein contacts occur in the RAD51 filament by means of the N-terminal domain of RAD51 for BRC3 and the nucleotide-binding core of RAD51 for BRC4. These observations show that the BRC repeats bind distinct regions of RAD51 and are nonequivalent in their mode of interaction. The results provide insight into why mutation in just one of the eight BRC repeats would affect the way that BRCA2 protein interacts with the RAD51 filament. Disruption of a single RAD51 interaction site, one of several simultaneous interactions occurring throughout the BRC repeat-containing exon 11 of BRCA2, might modulate the ability of RAD51 to promote recombinational repair and lead to an increased risk of breast cancer.     

Correlation of Antibodies to Neurotransmitters in the Sera of Women with Alcohol Dependence and Depressive Disorders

Bulletin of Experimental Biology and Medicine - Comparative analysis of blood sera from women with alcohol dependence and depressive disorders or from conditionally healthy women revealed reduced...