scholarly journals A single gene encodes two different transcripts for the ADP-glucose pyrophosphorylase small subunit from barley (Hordeum vulgare)

1996 ◽  
Vol 313 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Tine THORBJØRNSEN ◽  
Per VILLAND ◽  
Leszek A. KLECZKOWSKI ◽  
Odd-Arne OLSEN
Keyword(s):  
Hordeum Vulgare ◽  
Genomic Library ◽  
Single Gene ◽  
Starch Synthesis ◽  
Transit Peptide ◽  
Small Subunit ◽  
Peptide Sequence ◽  
Subunit Gene ◽  
Starchy Endosperm ◽  
Adp Glucose Pyrophosphorylase

ADP-glucose pyrophosphorylase (AGPase), a heterotetrameric enzyme composed of two small and two large subunits, catalyses the first committed step of starch synthesis in plant tissues. In an attempt to learn more about the organization and expression of the small-subunit gene of AGPase, we have studied the small-subunit transcripts as well as the structure of the gene encoding these transcripts in barley (Hordeum vulgare L. cv. Bomi). Two different transcripts (bepsF1 and blps14) were identified: bepsF1 was abundantly expressed in the starchy endosperm but not in leaves, whereas blps14 was isolated from leaves but was also found to be present at a moderate level in the starchy endosperm. The sequences for the two transcripts are identical over approx. 90% of the length, with differences being confined solely to their 5ʹ ends. In blps14, the unique 5ʹ end is 259 nt long and encodes a putative plastid transit peptide sequence. For the 178-nt 5ʹ end of bepsF1, on the other hand, no transit peptide sequence could be recognized. A lambda clone that hybridized to the AGPase transcripts was isolated from a barley genomic library and characterized. The restriction map has suggested a complex organization of the gene, with alternative exons encoding the different 5ʹ ends of the two transcripts followed by nine exons coding for the common part of the transcripts. The sequence of a portion of the genomic clone, covering the alternative 5ʹ-end exons as well as upstream regions, has verified that both transcripts are encoded by the gene. The results suggest that the small-subunit gene of barley AGPase transcribes two different mRNAs by a mechanism classified as alternative splicing.

Differential Processing of Homologues of the Small Subunit of ADP-Glucose Pyrophosphorylase from Barley (Hordeum vulgare) Tissues

1997 ◽  
Vol 52 (11-12) ◽  
pp. 807-811 ◽  
Author(s):  
Cheng Luo ◽  
Annabelle Déjardin ◽  
Per Villand ◽  
Danny N. P. Doan ◽  
Leszek A. Kleczkowski
Keyword(s):  
Hordeum Vulgare ◽  
Expression System ◽  
Starch Synthesis ◽  
Small Subunit ◽  
Proteolytic Processing ◽  
Differential Processing ◽  
E Coli ◽  
Barley Leaves ◽  
Molecular Masses ◽  
Adp Glucose Pyrophosphorylase

AbstractADP-glucose pyrophosphorylase (AGPase), a two-gene-encoded enzyme, is the key com­ponent of starch synthesis in all plants. In the present study, we have used an E. coli expression system for the (over)production of proteins derived from both full length and specifically truncated cDNAs encoding small subunits of AGPase from seed endosperm (AG Pase-Bl) and leaves (AGPase-B2) of barley (Hordeum vulgare). Based on immunoblot analyses, the molecular mass of the expressed A G Pase-Bl (52 kD) was similar to that from endosperm extracts, whereas the expressed AGPase-B2 (56 kD) was larger than that in barley leaves (51 kD). Expression of truncated cDNAs for both the seed and leaf proteins has allowed for a direct verification of molecular masses that were earlier proposed for mature AGPases in barley tissues. The data suggest that seed AGPase-B1 does not undergo any post-translational proteolytic processing in barley, whereas the leaf homologue is processed to a smaller protein. Possible implications of these findings are discussed.

Molecular Cloning and Spatial Expression of an ApL1 cDNA for the Large Subunit of ADP-Glucose Pyrophosphorylase from Arabidopsis thaliana

1999 ◽  
Vol 54 (5-6) ◽  
pp. 353-358 ◽  
Author(s):  
Leszek A. Kleszkowski ◽  
Lubomir N. Sokolov ◽  
Cheng Luo ◽  
Per Villand
Keyword(s):  
Arabidopsis Thaliana ◽  
Large Subunit ◽  
Critical Role ◽  
Starch Synthesis ◽  
Transit Peptide ◽  
Homologous Proteins ◽  
Peptide Cleavage ◽  
Reading Frame ◽  
Calculated Molecular Weight ◽  
Adp Glucose Pyrophosphorylase

Abstract A cDNA, A p L 1a , corresponding to a homologue of the large subunit of ADP-glucose pyrophosphorylase (AG Pase), has been isolated/characterised by screening a cDNA library prepared from leaves of Arabidopsis thaliana, followed by rapid amplification of cDNA 3′-ends (3′-RACE). Within the 1685 nucleotide-long sequence (excluding polyA tail), an open reading frame encodes a protein of 522 amino acids (aa), with a calculated molecular weight of 57.7 kDa. The derived aa sequence does not contain any discernible transit peptide cleavage site motif, similarly to two other recently sequenced full-length Arabidopsis homo-logues for AGPase, and shows ca. 58–78 % identity to homologous proteins from other plants/tissues. The corresponding gene was found (rosette and stem leaves, stems, flowers and fruits), consistent with its critical role in starch synthesis in

A mutant of rice lacking the leaf large subunit of ADP-glucose pyrophosphorylase has drastically reduced leaf starch content but grows normally

2007 ◽  
Vol 34 (6) ◽  
pp. 480 ◽  
Author(s):  
Sandrine Rösti ◽  
Brendan Fahy ◽  
Kay Denyer
Keyword(s):  
Environmental Conditions ◽  
No Reduction ◽  
Starch Content ◽  
Large Subunit ◽  
Starch Synthesis ◽  
Small Subunit ◽  
Wild Type ◽  
Gene Encoding ◽  
Subunit Protein ◽  
Adp Glucose Pyrophosphorylase

A mutant of rice was identified with a Tos17 insertion in OsAPL1, a gene encoding a large subunit (LSU) of ADP-glucose pyrophosphorylase (AGPase). The insertion prevents production of a normal transcript from OsAPL1. Characterisation of the mutant (apl1) showed that the LSU encoded by OsAPL1 is required for AGPase activity in rice leaf blades. In mutant leaf blades, the AGPase small subunit protein is not detectable and the AGPase activity and starch content are reduced to <1 and <5% of that in wild type blades, respectively. The mutation also leads to a reduction in starch content in the leaf sheaths but does not significantly affect AGPase activity or starch synthesis in other parts of the plant. The sucrose, glucose and fructose contents of the leaves are not affected by the mutation. Despite the near absence of starch in the leaf blades, apl1 mutant rice plants grow and develop normally under controlled environmental conditions and show no reduction in productivity.

scholarly journals Isolation and characterisation of the ADP-glucose pyrophosphorylase small subunit gene (AgpS1) promoter in tomato (Solanum lycopersicum L.)

2013 ◽  
Vol 30 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Yukihisa Goto ◽  
Satoko Nonaka ◽  
Yong-Gen Yin ◽  
Teruyuki Koiwa ◽  
Erika Asamizu ◽  
...  
Keyword(s):  
Solanum Lycopersicum ◽  
Small Subunit ◽  
Subunit Gene ◽  
Solanum Lycopersicum L ◽  
Adp Glucose Pyrophosphorylase

Cloning and expression analysis of cDNAs encoding ADP-glucose pyrophosphorylase large and small subunits from hulless barley (Hordeum vulgare L. var. nudum)

2018 ◽  
Vol 73 (5-6) ◽  
pp. 191-197 ◽  
Author(s):  
Dongmei Li ◽  
Zhimin Yang ◽  
Xinchun Liu ◽  
Zhen Song ◽  
Zongyun Feng ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Large Subunit ◽  
Starch Synthesis ◽  
Small Subunit ◽  
Cloning And Expression ◽  
Starch Accumulation ◽  
Hordeum Vulgare L ◽  
Hulless Barley ◽  
Expression Levels ◽  
Adp Glucose Pyrophosphorylase

Abstract As an important plateau cereal crop, hulless barley is the principal food for the Tibetan people in China. ADP-glucose pyrophosphorylase (AGPase) is considered as the key enzyme for starch biosynthesis in plants. In this study, cDNAs encoding the small subunit (SSU I) and large subunit (LSU I) of AGPase were isolated from hulless barley. The results showed that SSU I and LSU I were 1438 and 1786 bp in length with a complete open reading frame (ORF) of 1419 and 1572 bp. The ORF-encoded polypeptides of 472 and 523 amino acids were having calculated molecular masses of 52.01 and 58.23 kDa, and the pI values were 5.59 and 6.30. In addition, phylogenetic analysis showed that SSU I and LSU I had the same phylogenetic trends with some species. Furthermore, expression levels in different growth periods and tissues of two hulless barley varieties were analyzed by quantitative reverse transcription-polymerase chain reaction. Gene expression levels of SSU I and LSU I were consistent with the total starch accumulation rate in endosperm. In conclusion, our data confirmed that SSU I and LSU I played an important role in hulless barley starch synthesis.

Use of chimaeric genes harbouring small subunit transit peptide sequences to study transport in chloroplasts

1986 ◽  
Vol 313 (1162) ◽  
pp. 429-432 ◽  
Keyword(s):  
High Efficiency ◽  
Transit Peptide ◽  
Small Subunit ◽  
Peptide Sequence ◽  
Ribulose Bisphosphate Carboxylase ◽  
Bisphosphate Carboxylase ◽  
Quantitative Measurements ◽  
Marker Proteins ◽  
Necessary And Sufficient

A sequence coding for the transit peptide part of the precursor of the ribulose bisphosphate carboxylase small subunit can be used to construct chimaeric genes coding for easily detectable marker proteins. Chloroplasts of transgenic plants containing such chimaeric genes were found to contain the marker proteins. In addition, measurements of uptake by isolated chloroplasts of various precursor proteins, synthesized in vitro , demonstrated that most if not all of the transit peptide sequence was necessary and sufficient to obtain transport into chloroplasts. However, quantitative measurements of uptake indicated that high efficiency of transport required domains from both the transit peptide and the mature small subunit protein.

The folding capacity of the mature domain of the dual-targeted plant tRNA nucleotidyltransferase influences organelle selection

2013 ◽  
Vol 453 (3) ◽  
pp. 401-412 ◽  
Author(s):  
Matthew Leibovitch ◽  
Daniela Bublak ◽  
Pamela J. Hanic-Joyce ◽  
Bodo Tillmann ◽  
Nadine Flinner ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Physicochemical Properties ◽  
Single Gene ◽  
Transit Peptide ◽  
Intracellular Distribution ◽  
Peptide Sequence ◽  
Mature Protein ◽  
Nuclear Targeting ◽  
Mature Domain ◽  
Cellular Compartments

tRNA-NTs (tRNA nucleotidyltransferases) are required for the maturation or repair of tRNAs by ensuring that they have an intact cytidine-cytidine-adenosine sequence at their 3′-termini. Therefore this enzymatic activity is found in all cellular compartments, namely the nucleus, cytoplasm, plastids and mitochondria, in which tRNA synthesis or translation occurs. A single gene codes for tRNA-NT in plants, suggesting a complex targeting mechanism. Consistent with this, distinct signals have been proposed for plastidic, mitochondrial and nuclear targeting. Our previous research has shown that in addition to N-terminal targeting information, the mature domain of the protein itself modifies targeting to mitochondria and plastids. This suggests the existence of an as yet unknown determinate for the distribution of dual-targeted proteins between these two organelles. In the present study, we explore the enzymatic and physicochemical properties of tRNA-NT variants to correlate the properties of the enzyme with the intracellular distribution of the protein. We show that alteration of tRNA-NT stability influences its intracellular distribution due to variations in organelle import capacities. Hence the fate of the protein is determined not only by the transit peptide sequence, but also by the physicochemical properties of the mature protein.

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