First published online September 28, 2006
Development 133, 2005e (2006)
© The Company of Biologists Limited
Translational control gets a shunt
The green alga Volvox carteri, with its two distinct cell types -
somatic and reproductive cells - is an ideal organism in which to study the
molecular basis of cell differentiation. Somatic cell terminal differentiation
in Volvox is controlled by the transcriptional repressor RegA, which
stops these cells from becoming reproductive cells. Now, on
p. 4045, Babinger and
colleagues report that, surprisingly, the translation of regA is
controlled by ribosome shunting, a process in which the translation initiation
complex dissociates from the mRNA at a stable secondary structure and then
rebinds at a downstream `landing site'. Via a systematic mutational analysis
of the regA 5' UTR, which contains eight start codons, the
researchers discounted leaky scanning, reinitiation and internal ribosome
entry site-mediated initiation as the mechanisms that control regA
translation. Instead, their results indicate that regA translation is
controlled by ribosome shunting, an unusual mechanism in eukaryotes for
regulating translation that, the researchers suggest, might be used in other
developmental situations.
Related articles in Development:
- Translational control of regA, a key gene controlling cell differentiation in Volvox carteri
- Karin Babinger, Armin Hallmann, and Rüdiger Schmitt
Development 2006 133: 4045-4051.
[Abstract]
[Full Text]
