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 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

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