Taking a cellular road-trip: mRNA transport and anchoring.

mRNA localization is a crucial mechanism for post-transcriptional control of gene expression used in numerous cellular contexts to generate asymmetric enrichment of an encoded protein. This process has emerged as a fundamental regulatory mechanism that operates in a wide range of organisms to control an array of cellular processes. Recently, significant advances have been made in our understanding of the mechanisms that regulate several steps in the mRNA localization pathway.

Preparation of a highly active cell-free translation system from immature Xenopus laevis oocytes.

Understanding mechanisms of post-transcriptional control of gene expression has come under much scrutiny in recent years. A key question in this field is how the translation of specific mRNAs is activated or repressed both spatially and temporally in a given cell. In oocytes of the frog Xenopus laevis a number of mRNAs are localized early in oogenesis and subsequently translated at later stages.

Multiple kinesin motors coordinate cytoplasmic RNA transport on a subpopulation of microtubules in Xenopus oocytes.

RNA localization is a widely conserved mechanism for generating cellular asymmetry. In Xenopus oocytes, microtubule-dependent transport of RNAs to the vegetal cortex underlies germ layer patterning. Although kinesin motors have been implicated in this process, the apparent polarity of the microtubule cytoskeleton has pointed instead to roles for minus-end-directed motors.

Effects of a number of classes of 50S inhibitors on stop codon readthrough during protein synthesis.

The effect of a number of antibiotics on stop codon readthrough during protein synthesis in Escherichia coli was examined. Inhibitors which bind close to the entrance of the peptide exit tunnel on the 50S ribosomal subunit promote substantial levels of readthrough, presumably by disrupting the mechanism of peptide release.