[The influence of light, hormonal, and carbohydrate signal systems on ELIP genes expression in gun-mutants Arabidopsis thaliana].

It is proven that retrograde tetrapyrrole-induced plastid signals, light signals, and signals induced by hormones and carbohydrates influence expression of nuclear genes of plastid stress proteins ELIP in Arabidopsis thaliana L. Plastid signals differently regulated expression of genes from multigene family of photosynthesis proteins (ELIP and Lhcb2) and were modulated by light. The influence of a regulator of plant growth--abscisic acid--led to activation of expression of ELIP genes in the light. Carbohydrates suppressed transcription of ELIP genes. Thus, signals of exogenous (light) and endogenous (retrograde signals, hormones, carbohydrates) origin influence the expression of ELIP genes. These types of signals probably interact with each other and favor the increase of resistance of plants to the action of stress factors of the environment.

[The impact of melafen on the expression of chloroplastic chaperone protein HSP70B and photosynthetic pigments in cells of Chlamydomonas reinhardtii].

The effects of growth regulator of the new generation-melamine salt of bis(oxymethyl)phosphine acid (melafen)--on culture growth, pigment and protein content, and the induction of protective chloroplastic chaperone HSP70B in Chlamydomonas reinhardtii CW15 cells were studied. Melafen exhibited 10-30% growth inhibition at 10(-9)-10(-2)% concentration. At 10(-9)-10(-4)% of melafen electrophoretic concentration, the pattern of cellular proteins was similar to the control. The alterations in protein content of algae cells were detected only at 10(-2)% concentration. The content of chlorophyll and carotenoids in melafen-treated cells was 17-40% lower than in the control. Melafen at 10(-9)-109-2)% concentration inhibited HSP70B induction by 39-43% compared to untreated cells. The potential mechanism of melafen effect might involve its influence on nuclear gene expression.

[Mitochondrial signaling: retrograde regulation in yeast Saccharomyces cerevisiae].

The review considers the current views of the yeast signaling system that connects mitochondria with the nucleus and is known as retrograde regulation. The adaptive character of this signaling system is emphasized. The system is activated upon damage to mitochondrial functions (e.g., by stress or mutations) and is aimed at adapting the cell to the changed functional state of the organelles. The retrograde signaling system is controlled by positive (Rtglp, Rtg2p, Rtg3p, and Grr1p) and negative (Mks1p, Lst8p, Bmh1p, and Bmh2p) regulatory factors. The possibility of several retrograde pathways existing in mitochondria is discussed in brief. Data on some functions of retrograde regulation are described.

[Effect of melafen on expression of Elip1 and Elip2 genes encoding chloroplast light-induced stress proteins in barley].

The effect of melafen, a plant growth regulator of a new generation, on the growth, pigment composition, and expression of nuclear genes Elip1 and Elip2 encoding chloroplast light-stress proteins in barley (Hordeum vulgare L) seedlings was studied. It is shown that the height of seedlings treated with melafen at concentrations of 0.5 x 10(-10) and 0.5 x 10(-8) M increased by approximately 10 and 20%, respectively, as compared to the control. At high concentrations (10(-5) and 10(-3) M), melafen had no effect on the growth of seedlings. The content of chlorophylls and carotenoids in chloroplasts barely differed from the control at all melafen concentrations tested. Reverse transcription-polymerase chain reaction (RT-PCR) showed that melafen did not influence the expression of the nuclear gene encoding the low-molecular-weight plastid stress protein ELIP1. At the same time, the expression of the nuclear gene encoding the high-molecular-weight light-inducible stress protein ELIP2 in the plants treated with melafen at a concentration of 0.5 x 10(-8) M, increased by approximately 70 %. At higher concentrations, melafen suppressed the Elip2 gene expression. Thus, melafen affects the expression of the Elip2 gene, which is involved in the regulation of chlorophyll synthesis and chloroplast biogenesis, which, in turn, may lead to changes in the resistance of plants to light-induced stress.

[Tetrapyrrole involvement in expression regulation of a nuclear gene of low-molecular-weight plastid protein ELIP].

An inhibitor analysis was used for studying the tetrapyrrole role in the regulation of the expression of the nuclear gene encoding a low-molecular-weight protein, a stress plastid light-inducible protein ELIP. 2,2'-Dipyridyl and norflurazon were used as inhibitors. Experiments with dipyridyl demonstrated that tetrapyrroles were involved in the regulation of Elip gene expression, inhibiting it by approximately 50%. Similar results were obtained when there was photodestruction of the chloroplasts, caused by a plant treatment with norflurazon. The results confirm the involvement of the chloroplasts in the regulation of the nuclear gene expression coding for plastid proteins. Tetrapyrroles are important contributors to this process.

[Genomics and evolution of cellular organelles].

The structure, functions, and evolution of cellular organelles are reviewed. The mitochondrial genomes of eukaryotes differ considerably in size and structural organization mainly due to the length variation in noncoding regions and the presence of introns. The mitochondrial genomes of angiosperms are the largest and most complicated. Gene content in eukaryotic mitochondrial genomes is similar. They usually encode all types of rRNA, a complete or partial complement of tRNA, and a limited number of proteins essential for mitochondrial functions. In all eukaryotes studied, mitochondrial genomes code for two highly hydrophobic proteins involved in respiration, cytochrome b and subunit 1 of cytochrome oxidase. Genome structure and gene content in plastids, mainly in higher plant chloroplasts, are highly conserved. Plastid genomes of algae are more variable in gene composition and contain several unique genes absent in the chloroplast DNA of higher plants. Plastid genomes encode proteins involved in transcription and translation, as well as proteins of the photosynthetic apparatus. Both types of cellular organelles are supposed to be of endosymbiotic origin. Modern plastids originate from a cyanobacterial ancestor. Alpha-proteobacteria, especially the most mitochondrion-like rickettsia, gave rise to mitochondria. The origin of plastids of higher plants and green algae as a result of primary endosymbiosis and that of other algal lineages by secondary endosymbiosis are briefly discussed.

[Plastidic genome of higher plants and algae: structure and function]. / Genom plastid vysshikh rastenii i vodoroslei: struktura i funktsii.

The data on the structure and gene content in completely sequenced plastid (predominantly chloroplast) genomes of higher plants and algae are reviewed. In higher plants, genome structure and gene content are highly conserved. Plastid genomes of algae are less conserved and contain several unique genes, which are not found in chloroplast DNAs of higher plants. Plastid genomes encode proteins involved in transcription and translation, as well as proteins of the photosynthetic apparatus and photosynthetic metabolism. The problems of origin and evolution of plastids are briefly discussed. The data published by the first half of 2002 are presented. Use was made of databases OGMP (http://megasun.bch.umontreal.ca/ogmp/projects/other/cp_list.html) and NCBI (www.ncbi.nlm.nih.gov).

[The mitochondrial genome of protists]. / Genom mitokhondrii protistov.

The data on the structure and functions of the mitochondrial genomes of protists (Protozoa and unicellular red and green algae) are reviewed. It is emphasized that mitochondrial gene structure and composition, as well as organization of mitochondrial genomes in protists are more diverse than in multicellular eukaryotes. The gene content of mitochondrial genomes of protists are closer to those of plants than animals or fungi. In the protist mitochondrial DNA, both the universal (as in higher plants) and modified (as in animals and fungi) genetic codes are used. In the overwhelming majority of cases, protist mitochondrial genomes code for the major and minor rRNA components, some tRNAs, and about 30 proteins of the respiratory chain and ribosomes. Based on comparison of the mitochondrial genomes of various protists, the origin and evolution of mitochondria are briefly discussed.

[Isolation and partial characterization of DNA topoisomerase I from the nucleoids of white mustard chloroplasts]. / Vydelenie i chastichnaia kharakteristika DNK-topoizomerazy I iz nukleoidov khloroplastov gorchitsy.

DNA topoisomerase was isolated for the first time from nucleoids of white mustard (Sinapis alba L.) chloroplasts. The enzyme had a molecular weight of 70 kDa; it was ATP-independent, required the presence of mono- (K+) and bivalent (Mg2+) cations, and was capable of relaxing both negatively and positively supercoiled DNA. These results suggest that the enzyme isolated belongs to type IB DNA topoisomerases.

[Various luminescence characteristics of allocytoplasmic wheat hybrids]. / Nekotorye liuminestsentnye kharakteristiki allotsitoplazmaticheskikh gibridov pshenitsy.

Comparative studies of thermoluminescence and slow fluorescence induction were carried out on leaves of allocytoplasmic hybrids and standard regionalized wheat (cultivar Zarya). There are differences in luminescence indices between these objects correlated to the thermoluminescence and slow fluorescence induction methods. These differences allow estimation of the functional activity of the photosynthetic system. All studied allocytoplasmic hybrids exceeded the standard wheat in both luminescence indices FM/FT (slow fluorescence induction) and SA/Stot (thermoluminescence) and productivity (height of seedlings, number of ears and grains, grain mass, etc.). The highest values of FM/FT and SA/Stot and the lowest value of SC/Stot were recorded in the allocytoplasmic hybrid Igen 3 x Mironovskaya 808, which is characterized by the highest productivity.

[Mitochondrial ribosomes]. / Ribosomy mitokhondrii.

Some present-day conceptions on the structure and physiochemical and functional properties of mitochondrial ribosomes of higher and lower eukaryotes are reviewed. Mitochondrial ribosomes are compared to the ribosomes of prokaryotic and eukaryotic types and plastid ribosomes; biogenesis and functions of mitochondrial ribosomes are also discussed.

[Some structural properties of 80S acid protein from pea ribosomes]. / Nekotorye kharakteristiki struktury kislogo belka 80S-ribosom gorokha.

The 80S acid protein from pea ribosomes similar to the L7/L12 protein from E. coli was studied. This protein was found to be rich in alanine (18 mol.%) and to contain an acid amino acids excess over basic ones, the ratio of basic amino acids to acid ones was 0.42. As in the case of other eukaryotic L7/L12 homologs studied, the N-terminal amino acid of the protein is methionine. Using the double immunodiffusion technique, no crossreaction of E. coli anti-L7/L12 with 80S acid protein from pea ribosomes was observed. It was assumed that the protein molecule contains conservative sites responsible for the specific functioning of eukaryotic L7/L12 homologs.

[Acid proteins of eukaryotic cell ribosomes. Isolation of the protein similar to E. coli L7/L12 from 80S pea ribosomes]. / Kislye belki ribosom éukarioticheskikh kletok. Vydelenie belka, skhodnogo s L7/L12 E. coli, iz 80S-ribosom gorokha.

Using ethanol-salt extraction and ion-exchange chromatography, an acid protein was isolated from 80S pea ribosomes. The protein is localized in the large subunit, is phosphorylated and has a molecular weight of 14000 and pI of 4.7. These features and the results of a comparative study of tryptic hydrolysates of the plant protein and of the protein under study suggest that the latter is homologous to the ribosomal protein L7/L12 of a prokaryotic type.

[Comparison of histone-like proteins from blue-green algae with ribosomal basic proteins of alga and wheat germ histones]. / Sravnenie gistonopodobnykh belkov sine-zelenoi vodorosli Anacystis nidulans s osnovnymi belkami ribosom vodorosli i gistonami zarodyshei pshenitsy

Histone-like proteins was found in blue-green alga Anacystis nidulans, which has no nucleus. F2b2, F2a2, F2a1 fractions were found in histone-like algae proteins and no fraction F1. Content of basic amino acids (arginine being prevailing in algae protein) is quite identical in histone-like algae proteins and in wheat germs histones, while the content of acid amino acids is considerably higher in algae. The presence in procaryotic cells of basic proteins similar in a number of properties to histones of higher organisms suggests that these proteins are evolutionary precursors of eucaryotic histones.