Maintaining the structural integrity of the Bamboo mosaic virus 3' untranslated region is necessary for retaining the catalytic constant for minus-strand RNA synthesis.

Background: Bamboo mosaic virus (BaMV) and the Potato virus X (PVX) are members of the genus Potexvirus and have a single-stranded positive-sense RNA genome. The 3'-untranslated region (UTR) of the BaMV RNA genome was mapped structurally into ABC (a cloverleaf-like), D (a stem-loop), and E (pseudoknot) domains. The BaMV replicase complex that was isolated from the infected plants was able to recognize the 3' UTR of PVX RNA to initiate minus-strand RNA synthesis in vitro.

Hydrolysates of citrus plants stimulate melanogenesis protecting against UV-induced dermal damage.

The sun-tanning process occurs as a spontaneous response to ultraviolet (UV) irradiation. UV will induce tanning and DNA damage, processes that can lead to photoaging and skin disorders such as hyperpigmentation and cancer. The pigment melanin protects skin from UV damage; therefore, an efficient melanin-promoting suntan lotion could be highly beneficial.

The 3'-terminal sequence of Bamboo mosaic virus minus-strand RNA interacts with RNA-dependent RNA polymerase and initiates plus-strand RNA synthesis.

A 3'-terminal, 77-nucleotide sequence of Bamboo mosaic virus (BaMV) minus-strand RNA (Ba-77), comprising a 5' stem-loop, a spacer and a 3'-CUUUU sequence, can be used to initiate plus-strand RNA synthesis in vitro. To understand the mechanism of plus-strand RNA synthesis, mutations were introduced in the 5' untranslated region of BaMV RNA, resulting in changes at the 3' end of minus-strand RNA. The results showed that at least three uridylate residues in 3'-CUUUU are required and the changes at the penultimate U are deleterious to viral accumulation in Nicotiana benthamiana protoplasts.

Chloroplast phosphoglycerate kinase, a gluconeogenetic enzyme, is required for efficient accumulation of Bamboo mosaic virus.

The tertiary structure in the 3'-untranslated region (3'-UTR) of Bamboo mosaic virus (BaMV) RNA is known to be involved in minus-strand RNA synthesis. Proteins found in the RNA-dependent RNA polymerase (RdRp) fraction of BaMV-infected leaves interact with the radio labeled 3'-UTR probe in electrophoretic mobility shift assays (EMSA). Results derived from the ultraviolet (UV) cross-linking competition assays suggested that two cellular factors, p43 and p51, interact specifically with the 3'-UTR of BaMV RNA.

Structural and functional analysis of the cis-acting elements required for plus-strand RNA synthesis of Bamboo mosaic virus.

Bamboo mosaic virus (BaMV) has a single-stranded positive-sense RNA genome. The secondary structure of the 3'-terminal sequence of the minus-strand RNA has been predicted by MFOLD and confirmed by enzymatic structural probing to consist of a large, stable stem-loop and a small, unstable stem-loop. To identify the promoter for plus-strand RNA synthesis in this region, transcripts of 39, 77, and 173 nucleotides (Ba-39, Ba-77, and Ba-173, respectively) derived from the 3' terminus of the minus-strand RNA were examined by an in vitro RNA-dependent RNA polymerase assay for the ability to direct RNA synthesis.

Characterization of the infectivity of Bamboo mosaic virus with its correlation to the in vitro replicase activities in Nicotiana benthamiana.

In vitro RNA-dependent RNA polymerase (RdRp) transcription assay share an extremely useful system for studying the molecular mechanisms of replication of positive-sense RNA viruses such as Bamboo mosaic virus (BaMV). However, the obstacle encountered in this system is the inconsistency in the enzyme activity and the template specificity among different batches of the RdRp extracts. In order to overcome this obstacle, we designed experiments to study the functional dynamics of the BaMV RdRp in terms of its activity and specificity during the course of infection.