Journal Article

The translational apparatus of <i>Tortula ruralis</i>: polysomal retention of transcripts encoding the ribosomal proteins RPS14, RPS16 and RPL23 in desiccated and rehydrated gametophytes

Andrew J. Wood, R. Joel Duff and Melvin J. Oliver

in Journal of Experimental Botany

Published on behalf of Society for Experimental Biology

Volume 51, issue 351, pages 1655-1662
Published in print October 2000 | ISSN: 0022-0957
Published online October 2000 | e-ISSN: 1460-2431 | DOI: http://dx.doi.org/10.1093/jexbot/51.351.1655
The translational apparatus of Tortula ruralis: polysomal retention of transcripts encoding the ribosomal proteins RPS14, RPS16 and RPL23 in desiccated and rehydrated gametophytes

More Like This

Show all results sharing this subject:

  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Tortula ruralis (Syntrichia ruralis) is an important model system for the study of plant vegetative desiccation tolerance. One of the most intriguing aspects of desiccation-tolerant plants is the maintenance of key cellular components in stable and viable forms in the desiccated state, particularly those related to the translational apparatus (i.e. ribosomes and ribosomal RNAs). This study investigated the third integral component of the translational apparatus, the ribosomal proteins. Three T. ruralis cDNAs encoding predicted polypeptides with significant similarity to ribosomal proteins were isolated from a cDNA expression library derived from the polysomal, messenger ribonucleoprotein particle (mRNP) fraction of desiccated gametophytes; Rps14 and Rps16 encode the small‐subunit ribosomal proteins RPS14 and RPS16, respectively, and Rpl23 encodes the large‐subunit ribosomal protein RPL23. RPS14, RPS16 and RPL23, the deduced polypeptides, have predicted molecular masses of 14.4 kDa, 16.2 kDa and 14.9 kDa and predicted pI's of 11.08, 10.34 and 10.67, respectively. Phylogenetic analysis of the deduced amino acid sequences demonstrated that each of the T. ruralis proteins is most similar to ribosomal proteins from higher plants even though RPS14 and RPL23 show high divergence from their other plant counterparts. RNA blot hybridizations of RNAs present within the polysomal mRNP fraction (i.e. the 100 K×g pellet) demonstrated that Rps14, Rps16 and Rpl23 are expressed in moss gametophytes during a desiccation–rehydration cycle and, according to the prior cDNA classification scheme in T. ruralis, are constitutive clones. These findings clearly demonstrated that Rps14, Rps16 and Rpl23 transcripts are retained within the polysomal fractions of desiccated gametophytes.

Keywords: Desiccation; moss; ribosomal protein; Tortula ruralis; translation.; EST, expressed sequence tag; ORF, open reading frame

Journal Article.  4793 words.  Illustrated.

Subjects: Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.