A Dialogue in the Medical Perspective-Body Mass and Nutritional Status Disorders during the Development Period.

Eating disorders among children and youth are a serious social problem. The time of development is the starting point in shaping eating patterns. Proper nutrition provides the basis for psychophysical development.

Priming and realignment by the influenza a virus RdRp is dependent on the length of the host primers and the extent of base pairing to viral RNA.

Initiation of influenza A virus (IAV) transcription depends on RNA primers derived from host RNAs. During this process, some primers are elongated by a few nucleotides, realigned on the viral RNA templates (vRNA), and then used to initiate another round of transcription. Here, we used information on the host primers used by four IAV strains and four mini-replicons to investigate the characteristics of primer undergoing priming and realignment.

Insight into Influenza: A Virus Cap-Snatching.

The influenza A virus (IAV) genome consists of eight single-stranded RNA segments. Each segment is associated with a protein complex, with the 3' and 5' ends bound to the RNA-dependent RNA polymerase (RdRp) and the remainder associated with the viral nucleoprotein. During transcription of viral mRNA, this ribonucleoprotein complex steals short, 5'-capped transcripts produced by the cellular DNA dependent RNA polymerase II (RNAPII) and uses them to prime transcription of viral mRNA.

Influenza A virus cap-snatches host RNAs based on their abundance early after infection.

The influenza A virus RNA polymerase cleaves the 5' ends of host RNAs and uses these RNA fragments as primers for viral mRNA synthesis. We performed deep sequencing of the 5' host-derived ends of the eight viral mRNAs of influenza A/Puerto Rico/8/1934 (H1N1) virus in infected A549 cells, and compared the population to those of A/Hong Kong/1/1968 (H3N2) and A/WSN/1933 (H1N1). In the three strains, the viral RNAs target different populations of host RNAs.

Deep sequencing reveals the eight facets of the influenza A/HongKong/1/1968 (H3N2) virus cap-snatching process.

The influenza A virus RNA polymerase cleaves the 5' end of host pre-mRNAs and uses the capped RNA fragments as primers for viral mRNA synthesis. We performed deep sequencing of the 5' ends of viral mRNAs from all genome segments transcribed in both human (A549) and mouse (M-1) cells infected with the influenza A/HongKong/1/1968 (H3N2) virus. In addition to information on RNA motifs present, our results indicate that the host primers are divergent between the viral transcripts.

Identification of a binding site for ASF/SF2 on an RNA fragment derived from the hepatitis delta virus genome.

The hepatitis delta virus (HDV) is a small (~1700 nucleotides) RNA pathogen which encodes only one open reading frame. Consequently, HDV is dependent on host proteins to replicate its RNA genome. Recently, we reported that ASF/SF2 binds directly and specifically to an HDV-derived RNA fragment which has RNA polymerase II promoter activity.

The hepatitis delta virus RNA genome interacts with eEF1A1, p54(nrb), hnRNP-L, GAPDH and ASF/SF2.

Because of its extremely limited coding capacity, the hepatitis delta virus (HDV) takes over cellular machineries for its replication and propagation. Despite the functional importance of host factors in both HDV biology and pathogenicity, little is known about proteins that associate with its RNA genome. Here, we report the identification of several host proteins interacting with an RNA corresponding to the right terminal stem-loop domain of HDV genomic RNA, using mass spectrometry on a UV crosslinked ribonucleoprotein complex, RNA affinity chromatography, and screening of a library of purified RNA-binding proteins.