The University of Southampton
University of Southampton Institutional Repository

Bundle sheath defective2, a novel protein required for post-translational regulation of the rbcL gene of maize

Bundle sheath defective2, a novel protein required for post-translational regulation of the rbcL gene of maize
Bundle sheath defective2, a novel protein required for post-translational regulation of the rbcL gene of maize

The Bundle sheath defective2 (Bsd2) gene is required for ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) accumulation in maize. Using a Mutator transposable element as a molecular probe, we identified a tightly linked restriction fragment length polymorphism that cosegregated with the bsd2-conferred phenotype. This fragment was cloned, and sequences flanking the Mutator insertion were used to screen a maize leaf cDNA library. Using a full-length cDNA clone isolated in this screen, we show that an abundant 0.6-kb transcript could be detected in wild-type plants but not in bsd2-m1 plants. This 0.6-kb transcript accumulated to low levels in plants carrying an allele derived from bsd2-m1 that conditions a less severe mutant phenotype. Taken together, these data strongly suggest that we have cloned the Bsd2 gene. Sequence analysis of the full-length cDNA clone revealed a chloroplast targeting sequence and a region of homology shared between BSD2 and the DnaJ class of molecular chaperones. This region of homology is limited to a cysteine-rich Zn binding domain in DnaJ believed to play a role in protein-protein interactions. We show that BSD2 is targeted to the chloroplast but is not involved in general photosynthetic complex assembly or protein import. In bsd2 mutants, we could not detect the Rubisco protein, but the chloroplast-encoded Rubisco large subunit transcript (rbcL) was abundant and associated with polysomes in both bundle sheath and mesophyll cells. By characterizing Bsd2 expression patterns and analyzing the bsd2-conferred phenotype, we propose a model for BSD2 in the post-translational regulation of rbcL in maize.

1040-4651
849-864
Brutnell, Thomas P.
20649203-08a3-46c1-b1f5-e220062e2b02
Sawers, Ruairidh J.H.
97af8bdc-8c93-48a7-a5e3-d683f86f8f88
Mant, Alexandra
63319e45-deeb-45ad-a30d-e05b42052a0d
Langdale, Jane A.
5b88b412-d88c-4e2e-a420-c830a399cdf0
Brutnell, Thomas P.
20649203-08a3-46c1-b1f5-e220062e2b02
Sawers, Ruairidh J.H.
97af8bdc-8c93-48a7-a5e3-d683f86f8f88
Mant, Alexandra
63319e45-deeb-45ad-a30d-e05b42052a0d
Langdale, Jane A.
5b88b412-d88c-4e2e-a420-c830a399cdf0

Brutnell, Thomas P., Sawers, Ruairidh J.H., Mant, Alexandra and Langdale, Jane A. (1999) Bundle sheath defective2, a novel protein required for post-translational regulation of the rbcL gene of maize. The Plant Cell, 11 (5), 849-864. (doi:10.1105/tpc.11.5.849).

Record type: Article

Abstract

The Bundle sheath defective2 (Bsd2) gene is required for ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) accumulation in maize. Using a Mutator transposable element as a molecular probe, we identified a tightly linked restriction fragment length polymorphism that cosegregated with the bsd2-conferred phenotype. This fragment was cloned, and sequences flanking the Mutator insertion were used to screen a maize leaf cDNA library. Using a full-length cDNA clone isolated in this screen, we show that an abundant 0.6-kb transcript could be detected in wild-type plants but not in bsd2-m1 plants. This 0.6-kb transcript accumulated to low levels in plants carrying an allele derived from bsd2-m1 that conditions a less severe mutant phenotype. Taken together, these data strongly suggest that we have cloned the Bsd2 gene. Sequence analysis of the full-length cDNA clone revealed a chloroplast targeting sequence and a region of homology shared between BSD2 and the DnaJ class of molecular chaperones. This region of homology is limited to a cysteine-rich Zn binding domain in DnaJ believed to play a role in protein-protein interactions. We show that BSD2 is targeted to the chloroplast but is not involved in general photosynthetic complex assembly or protein import. In bsd2 mutants, we could not detect the Rubisco protein, but the chloroplast-encoded Rubisco large subunit transcript (rbcL) was abundant and associated with polysomes in both bundle sheath and mesophyll cells. By characterizing Bsd2 expression patterns and analyzing the bsd2-conferred phenotype, we propose a model for BSD2 in the post-translational regulation of rbcL in maize.

Full text not available from this repository.

More information

Published date: May 1999

Identifiers

Local EPrints ID: 413072
URI: http://eprints.soton.ac.uk/id/eprint/413072
ISSN: 1040-4651
PURE UUID: 6945b93a-ae1e-4480-81f2-426638a9fb9a
ORCID for Alexandra Mant: ORCID iD orcid.org/0000-0001-7169-209X

Catalogue record

Date deposited: 14 Aug 2017 16:31
Last modified: 07 Oct 2020 01:50

Export record

Altmetrics

Contributors

Author: Thomas P. Brutnell
Author: Ruairidh J.H. Sawers
Author: Alexandra Mant ORCID iD
Author: Jane A. Langdale

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×