The 3'-untranslated region of chloroplast psbA mRNA stabilizes binding of regulatory proteins to the leader of the message.
The 5'-leader and 3'-tail of chloroplast mRNAs have been suggested to play a role in posttranscriptional regulation of expression of the message. The regulation is thought to be mediated, at least in part, by regulatory proteins that are encoded by the nuclear genome and targeted to the chloroplast where they interact with chloroplast mRNAs. Previous studies identified high affinity binding of the 5'-untranslated region (UTR) of the chloroplast psbA mRNA by Chlamydomonas reinhardtii proteins. Here we tested whether the 3'-UTR of psbA mRNA alone or linked in cis with the 5'-UTR of the mRNA affects the high affinity binding of the message in vitro. We did not detect high affinity binding that is unique to the 3'-UTR. However, we show that the cis-linked 3'-UTR increases the stability of the 5'-UTR binding complex. This effect could provide a means for translational discrimination against mRNAs that are incorrectly processed.
Katz
Yael S
YS
Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Danon
Avihai
A
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D012333:RNA, Messenger