Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) hybridization in formamide at low temperature was applied to hybridization of PhiX174 replicative form DNA and in vivo PhiX174 specific messenger RNA (mRNA) with some modification. We found that PhiX174 mRNA up to molecular weight 1.2 x 10(6) could be hybridized to and eluted from DNA without apparent breakage of phosphodiester bonds and th...

Recent advances have led to a new understanding of how mRNAs are exported from the nucleus to the cytoplasm. This process requires a heterodimeric mRNA export receptor that is part of an elaborate machinery conserved from yeast to humans. Export of mRNAs is coupled to upstream steps in gene expression, such as pre-mRNA splicing, and to downstream events, including nonsense-mediated decay.

Pre-mRNA splicing has to be coordinated with other processes occurring in the nucleus including transcription, mRNA 3' end formation and mRNA export. To analyze the relationship between transcription and splicing, we constructed a network of nested introns. Introns were inserted in the 5' splice site and/or branchpoint of a synthetic yeast intron interrupting a reporter gene. The inserted intro...

GH receptor (GHR) has been reported to express in both normal rat and human adrenals. However, no study examined GHR expression in diseased human adrenal cortex. We quantitated, with RT-PCR, GHR messenger RNA (mRNA) in both normal and diseased human adrenal cortex with the following results: GHR mRNA levels in four histologically normal, not steroid-stimulated, control adrenal cortices was 1.5-...

Appropriate expression of most eukaryotic genes requires the removal of introns from their pre-messenger RNAs (pre-mRNAs), a process catalyzed by the spliceosome. In higher eukaryotes a large family of auxiliary factors known as SR proteins can improve the splicing efficiency of transcripts containing suboptimal splice sites by interacting with distinct sequences present in those pre-mRNAs. The...

The eukaryotic biological clock involves a negative transcription-translation feedback loop in which clock genes regulate their own transcription and that of output genes of metabolic significance. While around 10% of the liver transcriptome is rhythmic, only about a fifth is driven by de novo transcription, indicating mRNA processing is a major circadian component. Here, we report that inhibit...

In eukaryotic cells, the nuclear membrane creates a barrier between the nucleus and the cytoplasm. Whereas RNA synthesis occurs in the nucleus, they mostly function in the cytoplasm; thus export of RNA molecules from the nucleus to the cytoplasm is indispensable for normal function of the cells. The molecular mechanisms involved in each kind of cellular RNA export is gradually understood. The f...

Experiments that deal with the stability of messenger RNA (mRNA) in normal mouse kidney, and, to some extent, the stability of mRNA during renal growth will be described. We have found a population of mRNA in the cytoplasm of mouse kidney that is short-lived. Such a class of rapidly metabolized mRNA could play an adaptive role at the translational or cytoplasmic level in determining gene expres...

The messenger RNA processing reactions of capping, splicing, and polyadenylation occur cotranscriptionally. They not only influence one another's efficiency and specificity, but are also coordinated by transcription. The phosphorylated CTD of RNA polymerase II provides key molecular contacts with these mRNA processing reactions throughout transcriptional elongation and termination.

This article reviews a strategy to ensure long-term expression of a type of interfering RNA molecule-small-hairpin RNAs (shRNAs)-through the use of viral delivery systems (i.e., vectors). Expression of these shRNAs leads to the destruction of the intermediary molecules (i.e., messenger RNA [mRNA] molecules) generated during the expression of the target gene.