UV Turns on Translation

Science's STKE  18 Dec 2001:
Vol. 2001, Issue 113, pp. tw466
DOI: 10.1126/stke.2001.113.tw466

Levels of the RNA-binding heterogenous ribonucleoprotein A18 hnRNP are increased in response to ultraviolet (UV) light stress. Yang and Carrier developed an RNA-protein interaction screen to search for transcripts that may be regulated by this UV-inducible RNA-binding protein. Using their screen, they found specific binding of transcripts for several proteins and RNAs, including ribosomal proteins and stress-responsive proteins. Investigations of the binding site for two of these transcripts showed that A18 hnRNP binds the 3′ untranslated region. The levels of A18 hnRNP are not only increased by UV treatment, but the distribution of A18 hnRNP also changes in response to UV light, with the RNA-binding protein moving from the nucleus to the cytoplasm. The functional consequences of A18 hnRNP were analyzed by cotransfection of A18 hnRNP and a reporter gene and showed that A18 hnRNP increased both transcript levels (presumably by RNA stabilization) and protein expression of the reporter. Depletion of A18 hnRNP from cells by antisense techniques showed that the cells were less able to survive UV stress, suggesting that A18 hnRNP and the regulation of translation serves a protective role in response to stress conditions.

C. Yang, F. Carrier, The UV-inducible RNA-binding protein A18 (A18 hnRNP) plays a protective role in the genotoxic stress response. J. Biol. Chem. 276, 47277-47284 (2001) [Abstract] [Full Text]