Escherichia coli-based expression of functional novel DNA-binding histone H1 from Carassius auratus

A comprehensive review on histone-mediated transfection for gene therapy

Histone has been considered to be an effective carrier in non-viral gene delivery due to its unique properties such as efficient DNA binding ability, direct translocation to cytoplasm and favorable nuclear localization ability. Meanwhile, the rapid development of genetic engineering techniques could facilitate the construction of multifunctional fusion proteins based on histone molecules to further improve the transfection efficiency. Remarkably, histone has been demonstrated to achieve gene transfection in a synergistic manner with cationic polymers, affording to a significant improvement of transfection efficiency. In the review, we highlighted the recent developments and future trends in gene delivery mediated by histones or histone-based fusion proteins/peptides. This review also discussed the mechanism of histone-mediated gene transfection and provided an outlook for future therapeutic opportunities in the viewpoint of transfection efficacy and biosafety.

Analysis of the histone cluster in Senegalese sole (Solea senegalensis): evidence for a divergent evolution of two canonical histone clusters

The Senegalese sole (Solea senegalensis) is commercially very important and a priority species for aquaculture product diversification. The main histone cluster was identified within two BAC clones. However, two replacement histones (H1.0 and H3.3) were found in another BAC clone. Different types of canonical histones H2A and H2B were found within the same species for the first time. Phylogenetic analysis demonstrated that the different types of H1, H2A, and H2B histones were all more similar to each other than to canonical histones from other species. The canonical histone H3 of S. senegalensis differs from subtypes H3.1 and H3.2 in humans at the site of residue 96, where a serine is found instead of an alanine. This same polymorphism has been found only in Danio rerio. The karyotype of S. senegalensis comprises 21 pairs of chromosomes, distributed in 3 metacentric pairs, 2 submetacentric pairs, 4 subtelocentric pairs, and 12 acrocentric pairs. The two BAC clones that contain the clusters of canonical histones were both mapped on the largest metacentric pair, and mFISH analysis confirmed the co-location with the dmrt1 gene in that pair. Three chromosome markers have been identified which, in addition to those previously described, account for 18 chromosome pairs in S. senegalensis.

Isolation and characterization of the DNA and protein binding activities of adenovirus core protein V

The structure of adenovirus outer capsid was revealed recently at 3- to 4-Å resolution (V. Reddy, S. Natchiar, P. Stewart, and G. Nemerow, Science 329:1071-1075, 2010, http://dx.doi.org/10.1126/science.1187292); however, precise details on the function and biochemical and structural features for the inner core still are lacking. Protein V is one the most important components of the adenovirus core, as it links the outer capsid via association with protein VI with the inner DNA core. Protein V is a highly basic protein that strongly binds to DNA in a nonspecific manner. We report the expression of a soluble protein V that exists in monomer-dimer equilibrium. Using reversible cross-linking affinity purification in combination with mass spectrometry, we found that protein V contains multiple DNA binding sites. The binding sites from protein V mediate heat-stable nucleic acid associations, with some of the binding sites possibly masked in the virus by other core proteins. We also demonstrate direct interaction between soluble proteins V and VI, thereby revealing the bridging of the inner DNA core with the outer capsid proteins. These findings are consistent with a model of nucleosome-like structures proposed for the adenovirus core and encapsidated DNA. They also suggest an additional role for protein V in linking the inner nucleic acid core with protein VI on the inner capsid shell.

IMPORTANCE

Scant knowledge exists of how the inner core of adenovirus containing its double-stranded DNA (dsDNA) genome and associated proteins is organized. Here, we report a purification scheme for a recombinant form of protein V that allowed analysis of its interactions with the nucleic acid core region. We demonstrate that protein V exhibits stable associations with dsDNA due to the presence of multiple nucleic acid binding sites identified both in the isolated recombinant protein and in virus particles. As protein V also binds to the membrane lytic protein VI molecules, this core protein may serve as a bridge from the inner dsDNA core to the inner capsid shell.