The metabolites of the manumycin family are known to have a broad range of antibiotic functions including antibacterial, anticoccidial, and antifungal activities (1). Manumycin compounds also display a strong activity against farnesyltransferase, IB kinase ␤, interleukin-1␤-converting enzymes, and acetylcholinesterase and are considered as drug candidates to treat cancers, inflammation, and Alzheimer disease (1-4). Asukamycin A1, a manumycin-type metabolite, contains a unique 2-amino-4-hydroxy-5,6-epoxycyclohex-2-enone (mC 7 N) 3 core and two trans-triene polyketide chains, in which the upper one starts with a cyclohexane ring, and the lower one terminates in the five-membered ring of a 2-amino-3-hydroxycyclopent-2-enone (C 5 N) moiety (Fig.

Enterovirus 71 (EV71), a member of Picornaviridae, is associated with severe central nervous system complications. In this study, we identified a cellular microRNA (miRNA), miR-197, whose expression was downregulated by viral infection in a timedependent manner. In miR-197 mimic-transfected cells, EV71 replication was inhibited, whereas the internal ribosome entry site (IRES) activity was decreased in EV71 strains with or without predicted miR-197 target sites, indicating that miR-197 targets host proteins to modulate viral replication. We thus used a quantitative proteomics approach, aided by the TargetScan algorithm, to identify putative target genes of miR-197. Among them, RAN was selected and validated as a genuine target in a 3= untranslated region (UTR) reporter assay. Reduced production of RAN by RNA interference markedly reduced the synthesis of EV71-encoded viral proteins and virus titers. Furthermore, reintroduction of nondegradable RAN into these knockdown cells rescued viral protein synthesis. miR-197 levels were modulated by EV71 to maintain RAN mRNA translatability at late times postinfection since we demonstrated that cap-independent translation exerted by its intrinsic IRES activity was occurring at times when translation attenuation was induced by EV71. EV71-induced downregulation of miR-197 expression increased the expression of RAN, which supported the nuclear transport of the essential viral proteins 3D/3CD and host protein hnRNP K for viral replication. Our data suggest that downregulation of cellular miRNAs may constitute a newly identified mechanism that sustains the expression of host proteins to facilitate viral replication. IMPORTANCEEnterovirus 71 (EV71) is a picornavirus with a positive-sense single-stranded RNA that globally inhibits the cellular translational system, mainly by cleaving cellular eukaryotic translation initiation factor 4G (eIF4G) and poly(A)-binding protein (PABP), which inhibits the association of the ribosome with the host capped mRNA. We used a microRNA (miRNA) microarray chip to identify the host miRNA 197 (miR-197) that was downregulated by EV71. We also used quantitative mass spectrometry and a target site prediction tool to identify the miR-197 target genes. During viral infection, the expression of the target protein RAN was upregulated considerably, and there was a parallel downregulation of miR-197. The nuclear transport of viral 3D/3CD protein and of the host proteins involved in viral replication proceeded in an RAN-dependent manner. We have identified a new mechanism in picornavirus through which EV71-induced cellular miRNA downregulation can regulate host protein levels to facilitate viral replication. M icroRNAs (miRNAs) are a group of endogenous, highly conserved noncoding single-stranded RNAs (ϳ22 nucleotides [nt] in length) that are transcribed from specialized genes and undergo series processing to generate final mature miRNAs. The human genome contains more than 2,580 distinct mature miRNA genes (http://www.mirbase.org/) (1), which act as...

Background: Internal ribosomal entry sites (IRESs) provide alternative, cap-independent translation initiation sites in eukaryotic cells. IRES elements are important factors in viral genomes and are also useful tools for bi-cistronic expression vectors. Most existing RNA structure prediction programs are unable to deal with IRES elements.

The internal ribosomal entry site (IRES) functions as cap-independent translation initiation sites in eukaryotic cells. IRES elements have been applied as useful tools for bi-cistronic expression vectors. Current RNA structure prediction programs are unable to predict precisely the potential IRES element. We have designed a viral IRES prediction system (VIPS) to perform the IRES secondary structure prediction. In order to obtain better results for the IRES prediction, the VIPS can evaluate and predict for all four different groups of IRESs with a higher accuracy. RNA secondary structure prediction, comparison, and pseudoknot prediction programs were implemented to form the three-stage procedure for the VIPS. The backbone of VIPS includes: the RNAL fold program, aimed to predict local RNA secondary structures by minimum free energy method; the RNA Align program, intended to compare predicted structures; and pknotsRG program, used to calculate the pseudoknot structure. VIPS was evaluated by using UTR database, IRES database and Virus database, and the accuracy rate of VIPS was assessed as 98.53%, 90.80%, 82.36% and 80.41% for IRES groups 1, 2, 3, and 4, respectively. This advance useful search approach for IRES structures will facilitate IRES related studies. The VIPS on-line website service is available at http://140.135.61.250/vips/.

The detection of human papillomavirus (HPV) is very important for the evaluation of preventative strategies for cervical cancer. The major objective of this study was to characterize the prevalence of different genotypes of HPV in north Taiwan to contribute to the epidemiological knowledge of HPV infections. Papanicolaou (Pap) cervical smears were collected from 10,543 women aged between 14 and 87 years. The polymerase chain reaction (PCR) and DNA array hybridization techniques were used to genotype 51 different HPV strains. HPV was detected in 1,577 women, which gave an overall HPV prevalence rate of 15%. Forty-eight different genotypes were found in these patients, which included 9.7% that were high-risk HPV (HR-HPV) genotypes. The most common types of HR-HPV in patients, in descending order of frequency, were HPV 52, 16, 58, 56, 39, 51, 18, 68, 31, 33, 59, 45, and 35. HPV 52 was the most frequent type in every age group. The four most common HR-HPV types were found in 56.6% of the patients infected with HR-HPV. In cases that were infected with multiple HPV genotypes, 69.2% had at least one HR-HPV genotype. The rate of infection with HR-HPV was higher in the younger age groups than the older ones. In conclusion, 48 HPV genotypes were identified from a large study of cervical screening samples and the prevalence of HPV genotypes in different age groups was very diverse. The formulation of a public health strategy for HPV vaccination should take into account the prevalence of various HR-HPV/LR-HPV genotypes.