Distinct roles for the 5′ and 3′ untranslated regions in the degradation and accumulation of chloroplast tufA mRNA: identification of an early intermediate in the in vivo degradation pathway

Distinct roles for the 5′ and 3′ untranslated regions in the degradation and accumulation of... Elongation factor Tu in Chlamydomonas reinhardtii is a chloroplast-encoded gene (tufA) whose 1.7-kb mRNA has a relatively short half-life. In the presence of chloramphenicol (CAP), which freezes translating chloroplast ribosomes, a 1.5-kb tufA RNA becomes prominent. Rifampicin-chase analysis indicates that the 1.5-kb RNA is a degradation intermediate, and mapping studies show that it is missing 176–180 nucleotides from the 5′ end of tufA. The 5′ terminus of the intermediate maps to a section of the untranslated region (UTR) predicted to be highly structured and to encode a small ORF. The intermediate could be detected in older cultures in the absence of CAP, indicating that it is not an artifact of drug treatment. Also, it did not overaccumulate in the chloroplast ribosome-deficient mutant, ac20 cr1, indicating its stabilization is specific to elongation-arrested ribosomes. To determine if the 5′ UTR of tufA is destabilizing, the corresponding region of the atpA-aadA-rbcL gene was replaced with the tufA sequence, and introduced into the chloroplast genome; the 3′ UTR was also substituted for comparison. Analysis of these transformants showed that the transcripts containing the tufA 3′-UTR accumulate to significantly lower levels. Data from constructs based on the vital reporter, Renilla luciferase, confirmed the importance of the tufA 3′-UTR in determining RNA levels, and suggested that the 5′ UTR of tufA affects translation efficiency. These data indicate that the in vivo degradation of tufA mRNA begins in the 5′ UTR, and is promoted by translation. The data also suggest, however, that the level of the mature RNA is determined more by the 3′ UTR than the 5′ UTR. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Plant Molecular Biology Springer Journals

Distinct roles for the 5′ and 3′ untranslated regions in the degradation and accumulation of chloroplast tufA mRNA: identification of an early intermediate in the in vivo degradation pathway

Loading next page...
 
/lp/springer_journal/distinct-roles-for-the-5-and-3-untranslated-regions-in-the-degradation-0Bj7a8LWpi
Publisher
Kluwer Academic Publishers
Copyright
Copyright © 2006 by Springer Science+Business Media B.V.
Subject
Life Sciences; Plant Pathology; Biochemistry, general; Plant Sciences
ISSN
0167-4412
eISSN
1573-5028
D.O.I.
10.1007/s11103-006-9117-8
Publisher site
See Article on Publisher Site

Abstract

Elongation factor Tu in Chlamydomonas reinhardtii is a chloroplast-encoded gene (tufA) whose 1.7-kb mRNA has a relatively short half-life. In the presence of chloramphenicol (CAP), which freezes translating chloroplast ribosomes, a 1.5-kb tufA RNA becomes prominent. Rifampicin-chase analysis indicates that the 1.5-kb RNA is a degradation intermediate, and mapping studies show that it is missing 176–180 nucleotides from the 5′ end of tufA. The 5′ terminus of the intermediate maps to a section of the untranslated region (UTR) predicted to be highly structured and to encode a small ORF. The intermediate could be detected in older cultures in the absence of CAP, indicating that it is not an artifact of drug treatment. Also, it did not overaccumulate in the chloroplast ribosome-deficient mutant, ac20 cr1, indicating its stabilization is specific to elongation-arrested ribosomes. To determine if the 5′ UTR of tufA is destabilizing, the corresponding region of the atpA-aadA-rbcL gene was replaced with the tufA sequence, and introduced into the chloroplast genome; the 3′ UTR was also substituted for comparison. Analysis of these transformants showed that the transcripts containing the tufA 3′-UTR accumulate to significantly lower levels. Data from constructs based on the vital reporter, Renilla luciferase, confirmed the importance of the tufA 3′-UTR in determining RNA levels, and suggested that the 5′ UTR of tufA affects translation efficiency. These data indicate that the in vivo degradation of tufA mRNA begins in the 5′ UTR, and is promoted by translation. The data also suggest, however, that the level of the mature RNA is determined more by the 3′ UTR than the 5′ UTR.

Journal

Plant Molecular BiologySpringer Journals

Published: Dec 17, 2006

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve Freelancer

DeepDyve Pro

Price
FREE
$49/month

$360/year
Save searches from
Google Scholar,
PubMed
Create lists to
organize your research
Export lists, citations
Read DeepDyve articles
Abstract access only
Unlimited access to over
18 million full-text articles
Print
20 pages/month
PDF Discount
20% off