1
|
Suzuki Y, Ishiyama K, Yoon DK, Takegahara-Tamakawa Y, Kondo E, Suganami M, Wada S, Miyake C, Makino A. Suppression of chloroplast triose phosphate isomerase evokes inorganic phosphate-limited photosynthesis in rice. PLANT PHYSIOLOGY 2022; 188:1550-1562. [PMID: 34893891 PMCID: PMC8896644 DOI: 10.1093/plphys/kiab576] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/14/2021] [Indexed: 05/12/2023]
Abstract
The availability of inorganic phosphate (Pi) for ATP synthesis is thought to limit photosynthesis at elevated [CO2] when Pi regeneration via sucrose or starch synthesis is limited. We report here another mechanism for the occurrence of Pi-limited photosynthesis caused by insufficient capacity of chloroplast triose phosphate isomerase (cpTPI). In cpTPI-antisense transgenic rice (Oryza sativa) plants with 55%-86% reductions in cpTPI content, CO2 sensitivity of the rate of CO2 assimilation (A) decreased and even reversed at elevated [CO2]. The pool sizes of the Calvin-Benson cycle metabolites from pentose phosphates to 3-phosphoglycerate increased at elevated [CO2], whereas those of ATP decreased. These phenomena are similar to the typical symptoms of Pi-limited photosynthesis, suggesting sufficient capacity of cpTPI is necessary to prevent the occurrence of Pi-limited photosynthesis and that cpTPI content moderately affects photosynthetic capacity at elevated [CO2]. As there tended to be slight variations in the amounts of total leaf-N depending on the genotypes, relationships between A and the amounts of cpTPI were examined after these parameters were expressed per unit amount of total leaf-N (A/N and cpTPI/N, respectively). A/N at elevated [CO2] decreased linearly as cpTPI/N decreased before A/N sharply decreased, owing to further decreases in cpTPI/N. Within this linear range, decreases in cpTPI/N by 80% led to decreases up to 27% in A/N at elevated [CO2]. Thus, cpTPI function is crucial for photosynthesis at elevated [CO2].
Collapse
Affiliation(s)
- Yuji Suzuki
- Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Keiki Ishiyama
- Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan
| | - Dong-Kyung Yoon
- Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan
| | | | - Eri Kondo
- Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan
| | - Mao Suganami
- Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan
| | - Shinya Wada
- Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Chikahiro Miyake
- Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan
| | - Amane Makino
- Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan
| |
Collapse
|
2
|
Schmitz G, Schmidt M, Feierabend J. Characterization of a plastid-specific HSP90 homologue: identification of a cDNA sequence, phylogenetic descendence and analysis of its mRNA and protein expression. PLANT MOLECULAR BIOLOGY 1996; 30:479-492. [PMID: 8605300 DOI: 10.1007/bf00049326] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The isolation of cDNAs is described which encode the complete sequence of a precursor protein for a HSP90 homologue consisting of an N-terminal transit peptide of 5850 Da and a mature protein (cpHSP82) of 82 260 Da, located in the plastids of rye leaves (Secale cereale). Hybridization analysis indicated the presence of a single gene in the DNA of rye and a transcript size of 2.8 kb. A phylogenetic tree constructed on the basis of sequence comparisons for HSP90 homologues from different species and compartments indicated that the plastidic HSP82 from rye was more closely related to an eubacterial protein than to HSP90 homologues of the cytosol or ER from both plants and animals. The results suggest that during chloroplast evolution the gene for cpHSP82 was transferred to the nucleus from a prokaryotic endosymbiont. Immunoblots with specific antibodies and Percoll gradient-purified organelles confirmed the location of cpHSP82 in chloroplasts or non-green plastids. In green rye leaves cpHSP82 was constitutively expressed and equally distributed among tissues of different age. The expression of cpHSP82 was enhanced within 2 h by exposure to 42 degrees C. The cpHSP82 transcript and protein were much more strongly expressed in non-green tissues, such as etiolated, 70S ribosome-deficient 32 degrees C-grown, or herbicide-bleached, than in normal green leaves. Also chromoplasts from the pericarp of tomato fruits contained high levels of a HSP90 polypeptide while a photosynthetic protein, the large subunit of ribulose-1,5-bisphosphate carboxylase was largely degraded during ripening.
Collapse
Affiliation(s)
- G Schmitz
- Botanisches Institut, J.W. Goethe-Universität, Frankfurt am Main, Germany
| | | | | |
Collapse
|
3
|
Zhou YH, Ragan MA. Cloning and characterization of the nuclear gene and cDNAs for triosephosphate isomerase of the marine red alga Gracilaria verrucosa. Curr Genet 1995; 28:317-23. [PMID: 8590477 DOI: 10.1007/bf00326429] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
cDNAs and an intronless single-copy nuclear gene (TPI1) encoding triosephosphate isomerase have been cloned and sequenced from the marine red alga Gracilaria verrucosa. The predicted amino-acid sequence of TPI1 is readily alignable with those of other known TPIs; 26 of 27 active-site residues and 19 of 26 intersubunit-contact residues are identical between TPIs of G. verrucosa and/or animals and green plants. A partial cDNA sequence of a second TPI gene (TPI2), presumably encoding plastid-localized TPI, was recovered by PCR and demonstrated by phylogenetic analysis to be red algal; no TP12 cDNA or genomic clones could be recovered. Genomic Southern analysis demonstrated that at least two TPI-like genes are present in the nuclear DNA of G. verrucosa.
Collapse
Affiliation(s)
- Y H Zhou
- Institute for Marine Biosciences, National Research Council of Canada, Halifax, Nova Scotia, Canada
| | | |
Collapse
|
4
|
Schmidt M, Svendsen I, Feierabend J. Analysis of the primary structure of the chloroplast isozyme of triosephosphate isomerase from rye leaves by protein and cDNA sequencing indicates a eukaryotic origin of its gene. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1261:257-64. [PMID: 7711069 DOI: 10.1016/0167-4781(95)00015-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The primary structure of the chloroplast isozyme of triosephosphate isomerase from rye leaves was identified by protein and cDNA sequencing and compared to the deduced amino acid sequence of a cDNA for the cytosolic isozyme. The mature cytosolic and chloroplast isozyme proteins share 64% amino acid sequence identity. The cDNA for the chloroplast isozyme codes for a precursor protein consisting of an N-terminal transit peptide of Mr 4351 and a mature subunit of Mr 27,282. Southern blot analysis indicates that the two rye isozymes are encoded by two independent single genes. Amino acid residues or sequence regions of basic functional relevance in known triosephosphate isomerases are strictly conserved in the chloroplast isozyme. The chloroplast isozyme contains 6 cysteine residues, instead of 4 in the cytosolic isozyme. A cysteine at position 143 of the chloroplast isozyme appears to be modified. Phylogenetic trees constructed on the basis of sequence comparisons for triosephosphate isomerases from different species of all major taxonomic groups indicate that the chloroplast isozyme is much more closely related to eukaryotic cytosolic enzymes than to eubacterial enzymes. The results indicate that the nuclear gene for the chloroplast isozyme originated with that for the cytosolic isozyme through duplication of an ancestral eukaryotic gene, rather than through gene transfer from a prokaryotic endosymbiont.
Collapse
Affiliation(s)
- M Schmidt
- Botanisches Institut, J.W. Goethe-Universität, Frankfurt am Main, Germany
| | | | | |
Collapse
|
5
|
Henze K, Schnarrenberger C, Kellermann J, Martin W. Chloroplast and cytosolic triosephosphate isomerases from spinach: purification, microsequencing and cDNA cloning of the chloroplast enzyme. PLANT MOLECULAR BIOLOGY 1994; 26:1961-73. [PMID: 7858230 DOI: 10.1007/bf00019506] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Chloroplast and cytosolic triosephosphate isomerases from spinach were separated and purified to homogeneity. Both enzymes were partially sequenced by Edman degradation. Using degenerate primers designed against the amino acid sequences, a homologous probe for the chloroplast enzyme was amplified and used to isolate several full-size cDNA clones. Chloroplast triosephosphate isomerase is encoded by a single gene in spinach. Analysis of the chloroplast cDNA sequence in the context of its homologues from eukaryotes and eubacteria reveals that the gene arose through duplication of its preexisting nuclear counterpart for the cytosolic enzyme during plant evolution.
Collapse
Affiliation(s)
- K Henze
- Institut für Genetik, Technische Universität Braunschweig, FRG, Germany
| | | | | | | |
Collapse
|
6
|
Raines CA, Lloyd JC, Dyer TA. Molecular biology of the C3 photosynthetic carbon reduction cycle. PHOTOSYNTHESIS RESEARCH 1991; 27:1-14. [PMID: 24414440 DOI: 10.1007/bf00029971] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/1990] [Accepted: 09/30/1990] [Indexed: 06/03/2023]
Abstract
In recent years the enzymes of the C3 photosynthetic carbon reduction (PCR) cycle have been studied using the techniques of molecular biology. In this review we discuss the primary protein sequences and structural predictions that have been made for a number of these enzymes, which, with the input of crystallographic analysis, gives the opportunity to understand the mechanisms of enzyme activity.The genome organisation and gene structure of the PCR enzymes is another area which has recently expanded, and we discuss the regulation of the genes encoding these enzymes and the complex interaction of various factors which influence their expression.
Collapse
Affiliation(s)
- C A Raines
- Biology Department, University of Essex, Wivenhoe Park, CO4 3SQ, Colchester, UK
| | | | | |
Collapse
|
7
|
Winter U, Feierabend J. Multiple coordinate controls contribute to a balanced expression of ribulose-1,5-bisphosphate carboxylase/oxygenase subunits in rye leaves. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 187:445-53. [PMID: 2298218 DOI: 10.1111/j.1432-1033.1990.tb15324.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the leaves of rye (Secale cereale L.), control mechanisms acting at multiple molecular levels contribute to a coordinate expression of the subunit polypeptides of ribulose-1,5-bisphosphate carboxylase. The relevance and hierarchy of the different control steps were evaluated by comparing the time courses of changes in levels of translatable mRNA, rates of in vivo amino acid incorporation, and the turnover of subunit polypeptides after selective interference with translation at either cytoplasmic 80S ribosomes, or at the 70S ribosomes of the chloroplast, by compartment-specific inhibitors, or by the use of 70S-ribosome-deficient leaves. The latter were generated by growing the plants at a non-permissive elevated temperature of 32 degrees C. The rates of synthesis of the two ribulose-1,5-bisphosphate carboxylase subunits were most rapidly adapted to each other by translational controls. Within 0.5-2.5 h after selective inhibition of the synthesis of either subunit, that of the other subunit made in the unaffected compartment also declined by more than 90% without any marked change in its mRNA. After prolonged inhibition (24 h) of either cytoplasmic or chloroplast protein synthesis, the levels of mRNAs for both subunits were greatly diminished. In rye, the mRNA levels for both subunits changed under all experimental conditions tested in a closely parallel manner and appeared to be always maintained in a balanced, fairly constant ratio by strong coordinate controls. Even 70S-ribosome-deficient leaves contained mRNAs for both the small and the large subunits, although only in small amounts. The mRNAs for both subunits were also markedly further decreased in 70S-ribosome-deficient leaves after application of an inhibitor of cytoplasmic translation. MDMP [2-(4-methyl-2,6-dinitroanilino)-N-methylpropionamide], suggesting that the suppression of the large subunit mRNA in the plastids was not mediated through feedback effects of accumulating unassembled large subunits. Coordinate controls at both the mRNA and the translational level require a bidirectional exchange of regulatory signals between chloroplast and cytoplasm. However, these controls were not absolutely restrictive and allowed low rates of uncoupled synthesis of either large or small subunits. Large subunits made in the presence of MDMP were stable over 24 h. However, unassembled small subunits synthesized in 70S-ribosome-deficient leaves were degraded with a half-time of 10.5 h, in contrast to their behavior after integration into the holoprotein in normal leaves, where no turnover was detected. The proteolytic removal of surplus free small subunits is regarded as a final post-translational fine-tuning step to establish a balanced subunit stoichiometry in leaves.
Collapse
Affiliation(s)
- U Winter
- Botanisches Institut, J. W. Goethe-Universität, Frankfurt am Main, Federal Republic of Germany
| | | |
Collapse
|
8
|
|
9
|
|
10
|
Chao S, Raines CA, Longstaff M, Sharp PJ, Gale MD, Dyer TA. Chromosomal location and copy number in wheat and some of its close relatives of genes for enzymes involved in photosynthesis. ACTA ACUST UNITED AC 1989. [DOI: 10.1007/bf00332405] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
11
|
Feierabend J, Schlüter W, Tebartz K. Unassembled polypeptides of the plastidic ribosomes in heat-treated 70S-ribosome-deficient rye leaves. PLANTA 1988; 174:542-550. [PMID: 24221572 DOI: 10.1007/bf00634485] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/1987] [Accepted: 01/12/1988] [Indexed: 06/02/2023]
Abstract
The polypeptides of the subunits of 70S ribosomes isolated from rye (Secale cereale L.) leaf chloroplasts were analyzed by two-dimensional polyacrylamide gel electrophoresis. The 50S subunit contained approx. 33 polypeptides in the range of relative molecular mass (Mr) 13000-36000, the 30S subunit contained approx. 25 polypeptides in the range of Mr 13000-40500. Antisera raised against the individual isolated ribosomal subunits detected approx. 17 polypeptides of the 50S and 10 polypeptides of the 30S subunit in the immunoblotting assay. By immunoblotting with these antisera the major antigenic ribosomal polypeptides (r-proteins) of the chloroplasts were clearly and specifically visualized also in separations of leaf extracts or soluble chloroplast supernatants. In extracts from rye leaves grown at 32° C, a temperature which is non-permissive for 70S-ribosome formation, or in supernatants from ribosome-deficient isolated plastids, six plastidic r-proteins were visualized by immunoblotting with the anti-50S-serum and two to four plastidic r-proteins were detected by immunoblotting with the anti-30S-serum, while other r-proteins that reacted with our antisera were missing. Those plastidic r-proteins that were present in 70S-ribosome-deficient leaves must represent individual unassembled ribosomal polypeptides that were synthesized on cytoplasmic 80S ribosomes. For the biogenesis of chloroplast ribosomes the mechanism of coordinate regulation appear to be less strict than those known for the biogenesis of bacterial ribosomes, thus allowing a marked accumulation of several unassembled ribosomal polypeptides of cytoplasmic origin.
Collapse
Affiliation(s)
- J Feierabend
- Botanisches Institut, Johann Wolfgang Goethe-Universität, Postfach 111932, D-6000, Frankfurt am Main, Federal Republic of Germany
| | | | | |
Collapse
|
12
|
van Brederode J, Kamps-Heinsbroek R, Steyns J. Serological and genetical studies on the evolution of substrate specificity of flavone glycosyltransferase genes inSilene. ACTA ACUST UNITED AC 1987. [DOI: 10.1007/bf01942853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
Kwiatowski J, Kaniuga Z. Isolation and characterization of cytosolic and chloroplast isoenzymes of Cu,Zn-superoxide dismutase from tomato leaves and their relationships to other Cu,Zn-superoxide dismutases. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0167-4838(86)90107-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
14
|
Non-chloroplast α-1,4-glucan phosphorylase from pea leaves: characterization and in situ localization by indirect immunofluorescence. Biochim Biophys Acta Gen Subj 1986. [DOI: 10.1016/0304-4165(86)90270-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
15
|
Steup M, Schächtele C. α-1,4-glucan phosphorylase forms from leaves of spinach (Spinacia oleracea L.) : II. Peptide patterns and immunological properties. A comparison with other phosphorylase forms. PLANTA 1986; 168:222-231. [PMID: 24232025 DOI: 10.1007/bf00402967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/1985] [Accepted: 01/22/1986] [Indexed: 06/02/2023]
Abstract
Peptide patterns and immunological properties of the cytoplasmic and chloroplastic α-1,4-glucan phosphorylase (EC 2.4.1.1) from spinach leaves have been studied and were compared with those of phosphorylases from other sources. The two spinach leaf phosphorylases were immunologically different; a limited cross-reactivity was observed only at high antigen or antibody concentrations. Peptide mapping of the two enzymes resulted in complex patterns composed of more than 20 fragments; but no peptide was electrophoretically identical in both proteins. Approximately 13 to 15 of the fragments exhibited antigeneity but no cross-reactivity of any peptide was observed. Therefore, the two compartment-specific phosphorylase forms from spinach leaves represent isoenzymes possessing different primary structures. Peptide patterns of potato tuber and rabbit muscle phosphorylase were different from those of the two spinach leaf enzymes. Although the potato tuber phosphorylase resides in the plastidic compartment and is kinetically closely related to the chloroplastic spinach enzyme, it reacted more strongly with the anti-cytoplasmic-phosphorylase immunoglobulin G. Similar results were obtained with rabbit muscle phosphorylase. These observations support the assumption that the chloroplast-specific phosphorylase isoenzyme has a higher structural diversity than does the cytoplasmic counterpart.
Collapse
Affiliation(s)
- M Steup
- Botanisches Institut der Westfälischen Wilhelms-Universität, Schlossgarten 3, D-4400, Münster, Federal Republic of Germany
| | | |
Collapse
|
16
|
Kurzok HG, Feierabend J. Genetic control of triosephosphate isomerase isoenzymes in wheat and rye. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1986; 72:359-363. [PMID: 24247943 DOI: 10.1007/bf00288573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/27/1986] [Indexed: 06/02/2023]
Abstract
The patterns of chloroplastic and cytosolic isoenzymes of triosephosphate isomerase were analysed by immunoblotting in leaves of rye, wheat, and some species of Aegilops or Agropyrum. While rye contained solely one chloroplastic and one cytosolic isoenzyme, wheat had a much more complex pattern which can be explained by the presence of three genomes in 6 x wheats (AABBDD) with distinct triosephosphate isomerase genes that provided different subunit species for the dimeric isoenzyme molecules. The 6 × wheats contained five, the 4 × wheats three, and the 2 × wheats only one chloroplastic isoenzyme band. The isoenzyme patterns were in accordance with a potential origin of one of the three chloroplastic triosephosphate isomerase genes of 6 × wheats from an Aegilops ancestor. The descent of the other two genes was, however, not in accordance with common contentions on the general evolution of cultural wheats. In the reciprocal intergeneric hybrids Secalotricum and Triticale both the chloroplastic and the cytosolic isoenzyme patterns of rye and wheat were biparentally inherited, indicating that both isoenzymes were controlled by nuclear genes. When monitored by immunoblotting the chloroplastic triosephosphate isomerase isoenzymes may provide useful genetic markers.
Collapse
Affiliation(s)
- H G Kurzok
- Botanisches Institut der Johann-Wolfgang-Goethe-Universität, Postfach 1119 32, D-6000, Frankfurt/M, Federal Republic of Germany
| | | |
Collapse
|
17
|
Phenylalanyl-tRNA synthetase from chloroplasts of a higher plant (Phaseolus vulgaris). Purification and comparison of its structural, functional, and immunological properties with those of the enzymes from the corresponding cytoplasm, the cyanobacterium Anacystis nidulans, and the photosynthetic green sulfur bacterium Chlorobium limicola. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)35857-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
18
|
Höinghaus R, Feierabend J. Origin and developmental changes of envelope proteins and translocator activities from plastids of Secale cereale L. PLANTA 1985; 166:452-465. [PMID: 24241610 DOI: 10.1007/bf00391269] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/1985] [Accepted: 05/24/1985] [Indexed: 06/02/2023]
Abstract
To determine the sites of synthesis of chloroplast-envelope proteins, we have analysed several enzyme and translocator functions ascribed to the envelope membranes, and investigated the envelope polypeptide composition of plastids isolated from 70S ribosome-deficient leaves of rye (Secale cereale L.) generated by growing the plants at a temperature of 32°C. Since the ribosomedeficient plastids are also achlorophyllous in light-grown leaves, not only were chloroplasts from mature, green leaves used for comparison, but also those from yellowing, aged leaves as well as etioplasts from dark-grown leaves raised at a temperature of 22° C. A majority of the plastidenvelope polypeptides appeared to be of cytoplasmic origin. The envelopes of ribosome-deficient plastids possessed ATPase (EC 3.6.1.3) activity; this was not, however, dependent on divalent cations, in contrast to the Mn(2+)- or Mg(2+)-dependent ATPase which is associated with chloroplast envelopes. Adenylate kinase (EC 2.7.4.3) was present in the stromal fraction of ribosome-deficient plastids and the stromal form of this enzyme is, therefore, of cytoplasmic origin. In contrast to previous findings, adenylate kinase was not, however, specifically associated with the chloroplast-envelope membranes, either in rye or in spinach. Measurements of the uptake of L-[(14)C]-malate into ribosome-deficient plastids indicated the presence and cytoplasmic origin of the dicarboxylate translocator. Malate uptake into rye etioplasts was, however, low. The phosphate translocator was assayed by the uptake of 3-phospho-[(14)C]glycerate. While rapid 3-phosphoglycerate uptake was observed for rye chloroplasts and etioplasts, it was hardly detectable for ribosome-deficient, plastids and rather low for chloroplasts from aged leaves. A polypeptide of M r approx. 30000 ascribed to the phosphate translocator was greatly reduced in the envelope patterns of ribosome-deficient plastids and of chloroplasts from aged leaves.
Collapse
Affiliation(s)
- R Höinghaus
- Botanisches Institut, Johann-Wolfgang Goethe-Universität, Postfach 111932, D-6000, Frankfurt am Main, Federal Republic of Germany
| | | |
Collapse
|
19
|
Biekmann S, Feierabend J. Synthesis and degradation of unassembled polypeptides of the coupling factor of photophosphorylation CF1 in 70S ribosome-deficient rye leaves. EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 152:529-35. [PMID: 2865139 DOI: 10.1111/j.1432-1033.1985.tb09228.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The formation of polypeptides of the coupling factor CF1 was investigated in 70S ribosome-deficient rye leaves generated by growing the plants at a non-permissive elevated temperature of 32 degrees C, in order to analyse mechanisms coordinating subunit accumulation. Antibodies were raised in rabbits against total CF1 as well as against its five individual subunits purified from chloroplast thylakoids from rye leaves. Several immunological techniques applying these antibodies (immunoprecipitation, immunoblotting, antibody affinity chromatography) were unable to detect the presence of any of the CF1 subunits in heat-treated 70S ribosome-deficient leaves. After in vivo labeling with L-[35S]methionine and subsequent immunoprecipitation, however, radioactivity was found to be incorporated into the subunits gamma and delta, but not into alpha, beta and epsilon, in 70S ribosome-deficient leaves, demonstrating the cytoplasmic synthesis of CF1-gamma and CF1-delta. Chase experiments after in vivo labeling with L-[35S]methionine indicated that the unassembled subunits gamma and delta were rapidly and preferentially degraded, while they were stabilized when integrated into the complete CF1 complex in normal green leaves from permissive growth conditions. The apparent half-times of the unassembled subunits were 2 h for CF1-gamma and 4 h for CF1-delta in 32 degrees C-grown leaves. Several other, stromal, plastid proteins of cytoplasmic origin were stable in 32 degrees C-grown leaves during the period of chase. In etiolated leaves total CF1, including all subunits, appeared to be less stable than in green leaves grown under permissive temperature conditions in light. Rapid degradation of the excess of unassembled subunits is regarded as an important mechanism ensuring a constant stoichiometry and apparently synchronous development of CF1 subunits.
Collapse
|
20
|
Kurzok HG, Feierabend J. Comparison of a cytosolic and a chloroplast triosephosphate isomerase isoenzyme from rye leaves. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0167-4838(84)90264-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|