Dark-Induced Destabilization

Science's STKE  20 Feb 2001:
Vol. 2001, Issue 70, pp. tw3
DOI: 10.1126/stke.2001.70.tw3

Expression of the Ferredoxin-1 (Fed-1) gene product is regulated by photosynthetic activity at multiple levels: transcription, mRNA stability, and translation. Hansen et al. studied how the association of Fed-1mRNA with polyribosomes was regulated by photosynthesis and how this interaction influenced Fed-1 mRNA stability. Kinetic experiments with a Fed-1 internal light regulatory element (iLRE) fused to the chloramphenicol acetyltransferase gene showed that the reporter mRNA is released from the polyribosomes within minutes in the dark and that the mRNA can reassociate with the ribosomes upon reillumination. The degradation of the mRNA occurs after the ribosome disassociation, suggesting that Fed-1 mRNA is more stable when complexed with the polyribosomes. The regulation of translation by illumination and by its effects on the association of mRNA with the ribosome was not unique to Fed-1, but was also seen with several, but not all, nuclear-encoded genes involved in photosynthesis.

E. R. Hansen, M. E. Petracek, L.F. Dickey, W. F. Thompson, The 5' end of the pea Ferredoxin-1 mRNA mediates rapid and reversible light-directed changes in translation in tobacco. Plant Physiol. 125, 770-778 (2001). [Abstract] [Full Text]