Selective photo-cross-linking of 2'-O-psoralen-conjugated oligonucleotide with RNAs having point mutations

It has been reported that point mutations in genes are responsible for various cancers and the selective regulation of the gene expression is an important issue to develop a new type of anticancer drugs. In this report, we present a new type of antisense molecule that photo-cross-links to an oligoribonucleotide having a point mutation site in a sequence specific manner. 2'-O-psoralen-conjugated adenosine was synthesized in four steps from adenosine and introduced in the middle of an oligodeoxyribonucleotide (2'-Ps-oligo). Compared with 5'-O-psoralen-conjugated oligodeoxyribonucleotide (5'-Ps-oligo), which has a psoralen at the 5'-end, 2'-Ps-oligo more selectively photo-cross-linked to a pyrimidine base of the site of alteration from purine to pyrimidine in the oligoribonucleotide.     

Structure and Regulation of the Movement of Human Myosin VIIA

Human myosin VIIA (HM7A) is responsible for human Usher syndrome type 1B, which causes hearing and visual loss in humans. Here we studied the regulation of HM7A. The actin-activated ATPase activity of full-length HM7A (HM7AFull) was lower than that of tail-truncated HM7A (HM7AΔTail). Deletion of the C-terminal 40 amino acids and mutation of the basic residues in this region (R2176A or K2179A) abolished the inhibition. Electron microscopy revealed that HM7AFull is a monomer in which the tail domain bends back toward the head-neck domain to form a compact structure. This compact structure is extended at high ionic strength or in the presence of Ca²⁺. Although myosin VIIA has five isoleucine-glutamine (IQ) motifs, the neck length seems to be shorter than the expected length of five bound calmodulins. Supporting this observation, the IQ domain bound only three calmodulins in Ca²⁺, and the first IQ motif failed to bind calmodulin in EGTA. These results suggest that the unique IQ domain of HM7A is important for the tail-neck interaction and, therefore, regulation. Cellular studies revealed that dimer formation of HM7A is critical for its translocation to filopodial tips and that the tail domain (HM7ATail) markedly reduced the filopodial tip localization of the HM7AΔTail dimer, suggesting that the tail-inhibition mechanism is operating in vivo. The translocation of the HM7AFull dimer was significantly less than that of the HM7AΔTail dimer, and R2176A/R2179A mutation rescued the filopodial tip translocation. These results suggest that HM7A can transport its cargo molecules, such as USH1 proteins, upon release of the tail-dependent inhibition.     

Chiral superstructures of insulin amyloid fibrils

Hydrodynamic forces are capable of inducing structural order in dispersed solid phases, and of causing symmetry-breaking when chiral crystals precipitate from an achiral liquid phase. Until it was observed upon vortex-assisted fibrillation of insulin, such behavior had been thought to be confined to few unbiological systems. In this paper we are discussing chiroptical properties of two chiral variants of insulin amyloid, termed +ICD and -ICD, which form during the process of chiral bifurcation in vortexed solutions of aggregating insulin. As conventional measurements of circular dichroism of solid, anisotropic substances are particularly vulnerable to overlapping influences of linear birefringence and linear dichroism, we have employed complementary tools including dedicated universal chiroptical spectrophotometer to rule out such artifacts. We propose that the strong chiroptical properties of +ICD and -ICD insulin fibrils are an aspect of genuine superstructural chirality of amyloid fibrils and of powerful excitonic couplings taking place within them. A comparison of thioflavin T complexes with fibrils formed by insulin and polyglutamic acid suggests that the extrinsic Cotton effect stemming from the level of single twisted dye molecules is weaker, although diagnostically useful, and cannot account for the overall magnitude of ICD of the dye bound to ±ICD insulin amyloid.     

Syntheses of 2-deoxy-2,3-didehydro-N-acetylneuraminic acid analogues modified by N-sulfonylamidino groups at the C-4 position and biological evaluation as inhibitors of human parainfluenza virus type 1

Eleven novel sialidase inhibitors 9 and 10 with an N-sulfonylamidino group at the C-4 position of Neu5Ac2en 1 against human parainfluenza virus type 1 (hPIV-1) were synthesized using copper-catalyzed three-component coupling reactions, and their inhibitory activities against hPIV-1 sialidase were studied.     

Comparison of liver mitochondrial proteins derived from newborn cloned calves and from cloned adult cattle by two-dimensional differential gel electrophoresis

Aberrant reprogramming of donor somatic cell nuclei may result in many severe problems in animal cloning. The inability to establish functional interactions between donor nucleus and recipient mitochondria is also likely responsible for such a developmental deficiency. However, detailed knowledge of protein expression during somatic cell nuclear transfer (SCNT) in cattle is lacking. In the present study, variations in mitochondrial protein levels between SCNT‐derived and control cattle, and from calves derived by artificial insemination were investigated. Mitochondrial fractions were prepared from frozen liver samples and subjected to two‐dimensional (2‐D) fluorescence differential gel electrophoresis (DIGE) using CyDye? dyes. Protein expression changes were confirmed with a volume ratio greater than 2.0 (P < 0.05). 2D‐DIGE analysis revealed differential expression of three proteins for SCNT cattle (n = 4) and seven proteins for SCNT calves (n = 6) compared to controls (P < 0.05). Different protein patterning was observed among SCNT animals even if animals were generated from the same donor cell source. No differences were detected in two of the SCNT cattle. Moreover, there was no novel protein identified in any of the SCNT cattle or calves. In conclusion, variation in mitochondrial protein expression concentrations was observed in non‐viable, neonatal SCNT calves and among SCNT individuals. This result implicates mitochondrial‐related gene expression in early developmental loss of SCNT embryos. Comparative proteomic analysis represents an important tool for further studies on SCNT animals. Mol. Reprod. Dev. 78:263–273, 2011. © 2011 Wiley‐Liss, Inc.     

Functional and genetic survey of all known single-nucleotide polymorphisms within the human deoxyribonuclease I gene in wide-ranging ethnic groups

The single-nucleotide polymorphisms (SNPs) in the human DNase I gene (DNASE1) might be involved in susceptibility to some common diseases; however, only limited population data are available. Further, the effects of these SNPs on in vivo DNase I activity remain unknown. The genotype and haplotype of all the SNPs in DNASE1 were determined in 3 ethnic groups including 14 populations using newly developed methods. Together with our previous data on the nonsynonymous SNPs, two major haplotypes based on the five exonic SNPs were identified; genetic diversity in the Asian population was low. Among 10 SNPs, other than exonic SNPs in the gene, only 3 were polymorphic among all the populations. Haplotype distribution, based on all the polymorphic SNPs, was clarified to be generally varied in an ethnic-dependent manner. Thus, the genetic aspects of DNASE1 with regard to all the SNPs in wide-ranging ethnic groups could be first demonstrated. Further, there was no correlation of all the polymorphic SNPs other than nonsynonymous ones with serum DNase I activity levels. Polymorphic SNPs other than the exonic SNPs might not be directly related to common diseases through alterations in in vivo levels of the activity.     

Molecular analysis of X-linked inborn errors of purine metabolism: HPRT1 and PRPS1 mutations

Mutations of two enzyme genes, HPRT1 encoding hypoxanthine guanine phosphoribosyltransferase (HPRT) and PRPS1 encoding a catalytic subunit (PRS-I) of phosphoribosylpyrophosphate synthetase, cause X-linked inborn errors of purine metabolism. Analyzing these two genes, we have identified three HPRT1 mutations in Lesch-Nyhan families following our last report. One of them, a new mutation involving the deletion of 4224 bp from intron 4 to intron 5 and the insertion of an unknown 28 bp, has been identified. This mutation resulted in an enzyme polypeptide with six amino acids deleted due to abnormal mRNA skipping exon 5. The other HPRT1 mutations, a single base deletion (548delT, 183fs189X), and a point mutation causing a splicing error (532+1G>A, 163fs165X) were detected first in Japanese patients but have been reported in European families. On the other hand, in the analysis of PRPS1, no mutation was identified in any patient.