The isolation and sequence analysis of two seed-expressed acyl carrier protein genes from Brassica napus

Silva, J. de; Loader, Neil M.; Jarman, Carl; Windust, J.; Hughes, Stephen; Safford, Richard

doi:10.1007/bf00027499

Cited by 55 publications

(40 citation statements)

References 31 publications

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“…Southern blotting has confirmed that the oleosin gene under study is part of a multigene family with up to six loci per haploid genome. This gene multiplication is common to many embryo-specific genes [7,34,3] in B. ncO)us and may be a general mechanism for rapidly accumulating seed storage products in response to highly variable conditions within the developing seed. Southern blotting was also utilised to demonstrate that the previously reported cDNA is transcribed from the presented oleosin gene.…”

Section: Discussionmentioning

confidence: 99%

Cloning and characterisation of an oleosin gene from Brassica napus

Slocombe

et al. 1992

Plant Mol Biol

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The sequence of an oleosin gene from Brassica napus has been determined. This gene contains a single intron of 437 bp and encodes a polypeptide of 195 amino acids. The oleosin gene product has an estimated molecular mass of 21.5 kDa and consists of a highly hydrophobic central domain flanked by relatively polar N- and C-terminal domains. The central domain is highly conserved between all oleosins sequenced to date and contains a run of periodically spaced leucine residues similar to that of a leucine-zipper motif. The gene has been shown to be expressed specifically in the embryo, maximally between 9 and 11 weeks after flowering, i.e. during the seed desiccation stage. Two transcriptional start sites have been mapped to -70 and -21 of the ATG and a putative ABA-responsive element and three repeated motifs have been identified in the promoter. These short promoter sequences could correspond to regulatory elements responsible for embryo-specific gene expression. Up to six genes exist in the oleosin gene family.

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Section: Discussionmentioning

confidence: 99%

Cloning and characterisation of an oleosin gene from Brassica napus

Slocombe

et al. 1992

Plant Mol Biol

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“…Accumulating evidence shows that plastids represent the major site of de novo fatty acid synthesis (9,30). Acyl carrier protein is located in chloroplasts (31), and their cloned genes have a transit peptide sequence to enter into the plastid (32,33). The fatty acid synthetase is a dissociable type II enzyme, which is analogous to that of Escherichia coli and is located in plastids (9).…”

Section: Resultsmentioning

confidence: 99%

Compartmentalization of two forms of acetyl-CoA carboxylase in plants and the origin of their tolerance toward herbicides.

Konishi

Sasaki

1994

Proc. Natl. Acad. Sci. U.S.A.

224

175

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Acetyl-CoA carboxylase (ACCase, EC 6.4.1.2) catalyzes the synthesis of malonyl-CoA, the first intermediate in fatty acid synthesis. We studied the llization of two forms, the prokaryote and the eukaryote forms, of ACCase in pea leaves by comparing the blotin polypeptides of the two ACCases in protein extract from leaves and plastids.We found that the two forms of ACCase were in diferent cell compartments of pea leaves; the prokaryote form was in the plastids, and the eukaryote form was elsewhere, probably in the cytosol. This result suested the existence of two sites of malonyl-CoA thes. The Gramineae, such as rice and wheat, which lack the accD gene encoding one of the subunits ofthe prokaryote form ofACCase in their chloroplast genomes, did not have the prokaryote form of the enzyme but had the eukaryote form. The selectlve grass herbicides of the diphenoxyproponic acid type and the cyclohexanedione type, in vitro, inhibited plastidic ACCase of the eukaryote form from wheat but did not inhibit that of the prokaryote form from pea, suggeting that the origin of the tolerance of intact pea plant toward these herbicides is partly in the insensitivity of the prokaryote form of the enzyme. The origin of the susceptibility of the Gramineae plants toward these herbicides seems to lie in the presence of the herbicide-sensitive eukaryote form and the absence ofthe insenitive prokaryote form due to the lack of the accD gene in plastid.Acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) catalyzes the ATP-dependent carboxylation of acetyl-CoA to form malonyl-CoA. The reaction is the first committed step in the synthesis of fatty acid, providing the essential substrate for fatty acid synthesis. There are two forms of ACCase: a prokaryote form consisting of three protein components biotin carboxylase, carboxyltransferase, and biotin carboxylase carrier protein (1)-and a eukaryote form consisting of three functional domains on a single polypeptide (2-7). It has been believed that, in plants, plastids are the major site of fatty acid synthesis (8) and that only the eukaryote form ofthe enzyme in plastids participates in the synthesis (9, 10). Early studies reported the existence of the prokaryote form in the spinach chloroplast (11), but this finding has been dismissed because the prokaryote form has not yet been purified and the purified ACCases from various plants are all eukaryote form consisting of a subunit size of -200 kDa (5-7), like that of the mammal enzyme (2). ACCase gene encoding the 230-kDa polypeptide has been isolated from a photosynthetic eukaryote alga (12). This large polypeptide is probably nuclearencoded because this sequence is not found in the complete sequence ofchloroplast genomes (13-15). However, recently we have obtained evidence ofthe existence of the prokaryote form in pea chloroplasts by identifying one of the subunits of carboxyltransferase, the chloroplast-encoded accD protein (16). This finding supports the early studies and indicates the existence of two forms of ACCase in pea plants (16,17). ...

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“…Confirmation that rape thioesterase is indeed encoded by a multigene family was provided by Southern analysis of genomic DNA which suggested 8-10 gene copies. Previous studies on another fatty acid synthase (FAS) component from oil seed rape, acyl carrier protein, showed it to be encoded by a heterogeneous multigene family of some 35 members [6]. The observed heterogeneity may reflect the allotetra- Fig.…”

Section: N L 2 a A A G T T G T A T G C A A T G T A A T A C T T T T T mentioning

confidence: 99%

Isolation and characterization of two Brassica napus embryo acyl-ACP thioesterase cDNA clones

et al. 1993

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Acyl-ACP thioesterases are involved in regulating chain termination of fatty acid biosynthesis in plant systems. Previously, acyl-ACP thioesterase purified from Brassica napus seed tissue has been shown to have a high preference for hydrolysing oleoyl-ACP. Here, oligonucleotides derived from B. napus oleoyl-ACP thioesterase protein sequence data have been used to isolate two acyl-ACP thioesterase clones from a B. napus embryo cDNA library. The two clones, pNL2 and pNL3, contain 1642 bp and 1523 bp respectively and differ in the length of their 3' non-coding regions. Both cDNAs contain open reading frames of 366 amino acids which encode for 42 kDa polypeptides. Mature rape thioesterase has an apparent molecular weight of 38 kDa on SDS-PAGE and these cDNAs therefore encode for precursor forms of the enzyme. This latter finding is consistent with the expected plastidial location of fatty acid synthase enzymes. Northern blot analysis shows thioesterase mRNA size to be ca. 1.6 kb and for the thioesterase genes to be highly expressed in seed tissue coincident with the most active phase of storage lipid synthesis. There is some sequence heterogeneity between the two cDNA clones, but overall they are highly homologous sharing 95.7% identity at the DNA level and 98.4% identity at the amino acid level. Some sequence heterogeneity was also observed between the deduced and directly determined thioesterase protein sequences. Consistent with the observed sequence heterogeneity was Southern blot data showing B. napus thioesterase to be encoded by a small multi-gene family.

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The isolation and sequence analysis of two seed-expressed acyl carrier protein genes from Brassica napus

Cited by 55 publications

References 31 publications

Cloning and characterisation of an oleosin gene from Brassica napus

Cloning and characterisation of an oleosin gene from Brassica napus

Compartmentalization of two forms of acetyl-CoA carboxylase in plants and the origin of their tolerance toward herbicides.

Isolation and characterization of two Brassica napus embryo acyl-ACP thioesterase cDNA clones

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