[Proteinopathies--forms of neurodegenerative disorders with protein aggregation-based pathology].

A number of neurodegenerative disorders have recently been coalesced into a group of proteinopathies because of the similarity of molecular mechanisms underlying their pathogenesis. A key step in the development of proteinopathies is a structural change that triggers aggregation of proteins, which are intrinsically prone to form aggregates due to their physical and chemical properties. Present review is devoted to the recent progress in the field of proteinopathies with specific focus on properties of aggregate-prone proteins, main stages of the development of molecular pathology and the role of cellular clearance systems in progression of neurodegeneration. Recent modifications in the nomenclature of neurodegenerative diseases will also be addressed.

[Targeted inactivation of gamma-synuclein gene affects anxiety and exploratory behaviour of mice].

Gamma(gamma)-synuclein is a member of synuclein family of cytoplasmic and predominantly neuronal proteins found only in vertebrates. Gamma-synuclein is abundant in axons and presynaptic terminals of neurons localized in brain regions involved in emotions, learning and memory. However, the role of gamma-synuclein in these brain functions was not previously assessed. We have demonstrated for the first time that the loss of gamma-synuclein results in a significant increase in the level of orientation response in novel environment and decrease in the level of state anxiety.

[Modelling synucleinopathies in genetically modified animals--successes and failures].

The synuclein family and particularly alpha-synuclein takes a central part in etiology and pathogenesis of Parkinson's disease--one of the most common human neurodegenerative diseases. The pathological changes in certain other neurodegenerative diseases are also linked to changes in metabolism and function of alpha-synuclein, hence comprising a new group of diseases--synucleinopathies. The molecular and cellular mechanisms that are involved in the development of neurodegeneration in synucleinopathies are still largely unknown. As a result, the therapeutic approaches to the treatment of synucleinopathies are inadequately tampered. The development of models of neurodegenerative process in laboratory animals plays a crucial role in the study of these molecular mechanisms. Recently a special emphasis was placed on transgenic animal models with modified expression of genes, which mutations are associated with inherited forms of human neurodegenerative diseases. Current review is devoted to the analysis of different models of synucleinopathies as a result of genetic modifications of alpha-synuclein expression.

[Overexpression of a novel gene toothrin in Drosophila].

A newly found locus of the Drosophila melanogaster genome, named toothrin (tth) has been used to study the role of the conserved domain 2/3 of genes from the d4 family. In contrast to the 2/3 domain of all vertebrates studied (including humans), which is always accompanied by the d4 domain, the tth gene contains the sequence encoding the 2/3 domain but lacks that encoding the d4 domain. The tth gene overexpression has been studied using the two-component system UAS-GAL4. It has been demonstrated that the tth overexpression at the third-instar larval (prepupal) stage decreases survival rate, simultaneously causing a substantial deceleration of development in Drosophila. It is known that the change of developmental stages in Drosophila is controlled by the rates of the expression of ecdysteroid and juvenile hormones (JHs). It is supposed that the overexpression of the tth gene causes either a shift in the ecdysterone-to-JH ratio (through a decreased JH decay rate or a delayed initiation of ecdysone synthesis) or a deceleration of the release of ecdysterones synthesized.

[Synucleins--to have or not to have]. / Sinukleiny--imet' ili ne imet'?

Synucleins, a protein family little known even three years ago, became extremely popular after two discoveries. First, alpha-synuclein was found to be involved in etiology and pathogenesis of neurodegenerative disorders. Second, some newly discovered synucleins were found to participate in development and function of certain divisions of the nervous system and some other tissues, as well as in malignisation of breast tumors. It is now evident that synucleins are a fundamentally new group of proteins. Despite the striking similarity of their amino-acid sequences, they have diverse and multiple functions. An important challenge for biomedical science is to understand functions of sinucleins in normal cells and their role in pathology.

[Cloning genes, specifically expressed in the cerebral cortex and cerebellum of adult rats]. / Klonirovanie genov, spetsificheski ékspressiruiushchikhsia v kore golovnogo mozga i mozzhechke vzroslykh krys.

To isolate genes differentially expressed in the rat brain cortex and cerebellum, a subtractive cDNA cloning procedure requiring only small quantities of poly(A+) RNA, followed by differential screening, was used. Two novel genes, MK and 3L7, with cortex- and cerebellum-specific expression were identified. These genes displayed different expression patterns in the brain cortex, cerebellum, and hippocampus during postnatal development.

[Cloning of genes, differentially expressed in the cerebellum during postnatal rat development]. / Klonirovanie genov, differentsioal'no ékspressiruiushchikhsia v mozzhechke postnatal'nom razvitii krys.

To identify genes differentially expressed in the developing rat cerebellum, a subtractive cDNA cloning procedure, followed by differential screening, was used. Four novel genes, MB, MF, 3E7, and 3C6, the transcriptional activity of which changed by a factor of five during cerebellar development, were isolated. The genes obtained were differentially expressed in different regions of the central nervous system. Variations in the levels of corresponding transcripts in the brain cortex and cerebellum were also recorded during postnatal rat development.

[Tissue-specific blocking of the EcoRI site adjacent to the pseudogene for mouse oncoprotein p53]. / Tkanespetsificheskoe blokirovanie EcoRI-saita vblizi psevdogena onkobelka p53 myshi.

EcoRI fragments of DNA isolated from the different mouse organs were hybridized to radioactivity labelled probe specific for the gene of oncoprotein p53. The analysis of the blot-hybridization points to the existence of the specific blockage of an EcoRI site flanking a 3.3 kb fragment of DNA including the pseudogene p53, isolated from the skin tissue. The existence of a polymorphous EcoRI site localized distally to the pseudogene p53 has been demonstrated in the DNA of mice of different lines.

[Effect of camptothecin on the DNA-relaxing and DNA-cleavage activity of calf thymus topoisomerase I]. / Vliianie kamptotetsina na DNK-relaksiruiushchuiu i DNK-rasshchepliaiushchuiu aktivnosti topoizomerazy I iz timusa telenka.

Nucleotide sequences that are cleaved by calf thymus type I topoisomerase have been determined using cloned human Ha-ras and p53 genes. Localization and relative frequency of single-strand cleavages within these sequences were observed to change in the presence of the cytotoxic alkaloid camptothecin.

[Two allelic genes of human p53 code for proteins differing with respect to amino acid sequence]. / Dva allel'nykh gena p53 cheloveka kodiruiut belki, razlichaiushchiesiapo aminokislotnoi posledovatel'nosti.

Two allelic p53 genes were investigated. The allelic gene with BgIII site in the first intron codes for faster p53 protein variant, the other allelic gene coding for slower p53 protein variant (according to the mobility in SDS-PAAG). Exons and flanked regions of introns were sequenced. In coding regions allelic genes only differ by second nucleotides of codon 72 (G----C), which leads to the change in amino acid sequence (Arg----Pro). The relationship of these changes and the function of p53 is discussed.

[Exon-intron structure and organization of the 5'-terminal region of the human p53 gene]. / Ekzon-intronnaia struktura i organizatsiia 5'-kontsevoi oblasti gena p53 cheloveka.

S1 mapping and nucleotide sequencing were used for localization of exon-intron junctions of the human p53 gene. The 3'-end of the gene was localized 12 nucleotides downstream AATAAA sequence, though an mRNA, 94 nucleotides shorter, was observed in one tumor. No typical promoter sequences were found at the 5'-end of the gene. In cell-free HeLa extracts transcription of RNA initiates within the sequence of possible hairpin-loop structure. Organization of the promoter region of the human p53 gene is discussed.

[Isolation and characteristics of clones complementary to mRNA of the murine cellular tumor antigen p53]. / Vydelenie i kharakteristika klonov, komplementarnykh mRNK myshinogo kletochnogo opukholevogo antigena p53.

43 cDNA clones specific for murine cellular tumor antigen p53 were isolated from a library constructed using 17S fraction of mRNA from the SV40 transformed murine fibroblasts (SVT2). These clones contain the whole coding region of p53 mRNA and the most of non-translated sequences. A plasmid containing 1.8 kb insert of p53 cDNA was constructed. The p53 specific insert in this plasmid was colinear with p53 mRNA, as revealed by S1 nuclease analysis. 5'-region of the p53 gene comprising non-translated and promoter areas was cloned from the mouse genomic library. A combined clone containing promoter and the whole region, corresponding to p53 mRNA has been constructed.

[Structural organization of the human p53 gene. I. Molecular cloning of the human p53 gene]. / Strukturnaia organizatsiia gena p53 cheloveka. Soobshchenie I. Molekuliarnoe klonirovanie gena p53 cheloveka.

Human p53 gene was cloned from the normal human placenta DNA and DNA from the strain of human kidney carcinoma transplanted into nude mice. Representative gene library from tumor strain of human kidney carcinoma and library of 15 kb EcoRI fragments of DNA from normal human placenta were constructed. Maniatis gene library was also used. Five clones were isolated from kidney carcinoma library; they covered 27 kb and included full-length p53 gene of 19.5 kb and flanking sequences. From normal placenta libraries three overlapped clones were obtained. Restriction map of cloned sequences was constructed and polarity of the p53 gene determined. The first intron of the gene is large (10.4 kb); polymorphic BglII site was observed in this intron, which allows to discriminate between allelic genes. One of these (BglII-) is ten times more abundant that the other (BglII+). Both allelic genes are able to synthesize the 2.8 kb p53 gene.

[Molecular causes of thalassemia. IV. Cloning of the beta-globin gene in a patient with beta-thalassemia from Azerbaijan and determination of the point mutation in a minor intron]. / Izuchenie molekuliarnykh prichin talassemii. Soobshchenie IV. Kloniovanie beta-globinovogo gena bol'nogo beta-talassemiei iz Azerbaidzhana i opredelenie tochkovoi mutatsii v malom introne.

On the basis of DNA from a beta-thalassemic patient, human gene library has been obtained using bacteriophage lambda EMBL4 as a vector. The recombinants contain human DNA insertions of 15 to 20 kb. The lambda A1 beta 1 clone has been isolated by the method of hybridization of phage plaque replicas to the HhaI fragment of JW102 plasmid containing human beta-globin cDNA. Restriction mapping revealed the presence of a 22 kb human DNA fragment comprising a portion of the beta-globin gene system. Subcloned fragments of beta-globin gene (within the pUC19 plasmid or phage MI3mp10) were sequenced using the Maxam and Gilbert method as well as that of Sanger. 2150 nucleotides in total were analysed. We have detected the point substitution G----A in the 110 nucleotide of minor intron, leading to the formation of an additional splicing site.

[Interaction of subunits of cAMP-dependent protein kinase with structural elements of the cell nucleus]. / Izuchenie vzaimodeistviia sub''edinits cAMP-zavisimoi proteinkinazy so strukturnymi élementami iadra.

Using the method of protein transfer from polyacrylamide gel to nitrocellulose filters with subsequent incubation of filter-adsorbed protein with [32P]DNA, it was found that the catalytic subunit of cAMP-dependent protein kinase from porcine brain is capable of interacting with DNA to form a stable complex. This complex is resistant even to 2 M NaCl. The ability of the catalytic subunit to interact with DNA depends on the degree of enzyme nativity. The regulatory subunit of cAMP-dependent protein kinase does not bind to DNA both in the presence and absence of cAMP. The 125I-labeled regulatory subunit can interact with some chromatin proteins, in particular, with histone H1 and core histones. An essential role in this binding belongs to electrostatic and hydrophobic interactions.

[Identification of histone mRNA and isolation of a DNA fraction enriched with Physarum polycephalum histone genes]. / Identifikatsiia gistonovykh mRNK i vydelenie fraktsii DNK, obogashchennoi gistonovymi genami Physarum polycephalum.

The 7-14S poly A- RNA isolated from the S-state polysomes of the macroplasmodium P. polycephalum reveals the properties of histone mRNA. In the wheat germ cell-free system this RNA is translated into the polypeptides with the same electrophoretic mobility as core histones of P. polycephalum. Using centrifugation in a CsCl density gradient with actinomycin D, a DNA fraction was isolated which hybridizes with cDNA synthesized at 7-14S poly A- RNA by reverse transcription with random priming. The DNA fraction formed can be used for cloning of P. polycephalum histone genes.