Journal article
Refine
Year of publication
Document Type
- Journal article (8463) (remove)
Language
Keywords
- Organische Chemie (122)
- Anorganische Chemie (119)
- Toxikologie (112)
- Medizin (98)
- inflammation (86)
- Biochemie (81)
- Chemie (68)
- cancer (66)
- gene expression (62)
- Psychologie (61)
Institute
- Theodor-Boveri-Institut für Biowissenschaften (1400)
- Institut für Psychologie (391)
- Institut für Anorganische Chemie (383)
- Physikalisches Institut (377)
- Medizinische Klinik und Poliklinik II (353)
- Neurologische Klinik und Poliklinik (351)
- Medizinische Klinik und Poliklinik I (333)
- Institut für Organische Chemie (316)
- Institut für Molekulare Infektionsbiologie (304)
- Klinik und Poliklinik für Psychiatrie, Psychosomatik und Psychotherapie (259)
Sonstige beteiligte Institutionen
- Johns Hopkins School of Medicine (11)
- IZKF Nachwuchsgruppe Geweberegeneration für muskuloskelettale Erkrankungen (7)
- Clinical Trial Center (CTC) / Zentrale für Klinische Studien Würzburg (ZKSW) (5)
- Wilhelm-Conrad-Röntgen-Forschungszentrum für komplexe Materialsysteme (5)
- Bernhard-Heine-Centrum für Bewegungsforschung (4)
- Johns Hopkins University School of Medicine (4)
- Zentraleinheit Klinische Massenspektrometrie (4)
- Center for Interdisciplinary Clinical Research, Würzburg University, Würzburg, Germany (2)
- Interdisciplinary Center for Clinical Research (2)
- Interdisziplinäres Zentrum für Klinische Forschung (IZKF) (2)
ResearcherID
- D-1221-2009 (1)
Although evidence obtained with the PC12 cell line has suggested a role for the ras oncogene proteins in the signal transduction of nerve growth factor-mediated fiber outgrowth, little is known about the signal transduction mechanisms involved in the neuronal response to neurotrophic factors in nontransformed cells. We report here that the oncogene protein T24-ras, when introduced into the cytoplasm of freshly dissociated chick embryonic neurons, promotes the in vitro survival and neurite outgrowth of nerve growth factor-responsive dorsal rootganglion neurons, brain-derived neurotrophic factor-responsive nodose ganglion neurons, and ciliary neuronotrophic factor-responsive ciliary ganglion neurons. The proto-oncogene product c-Ha-ras also promotes neuronal survival, albeit less strongly. No effect could be observed with truncated counterparts of T24-ras and c-Ha-ras lacking the 23 C-terminal amino acids including the membrane-an-choring, palmityl-accepting cysteine. These results sug-gest a generalized involvement of ras or ras-like proteins in the intracellular signal transduction pathway for neurotrophic factors.
The period of natural cell death in the development of rodent motor neurons is followed by a period of sensitivity to axonal injury1-3. In the rat this early postnatal period of vulnerability coincides with that of very low ciliary neurotrophic factor (CNTF) levels in the sciatic nerve before CNTF increases to the high, adult levels4. The developmental time course of CNTF expression, its regional tissue distribution and its cytosolic localization (as suggested by its primary structure)4*5 favour a role for CNTF as a lesion factor rather than a target-derived neurotrophic molecule like nerve growth factor. Nevertheless CNTF exhibits neurotrophic activity in vitro on different populations of embryonic neurons6. To determine whether the vulnerability of motor neurons to axotomy in the early postnatal phase is due to insufficient availability of CNTF, we transected the axons of newborn rat motor neurons and demonstrated that iocal application of CNTF prevents the degeneration of the corresponding cell bodies.
The occurrence of stacked annulate tamellae is documented for a plant cell system, namely for pollen mother cells and developing pollen grains of Canna generalis. Their structural subarchiteeture and relationship to endoplasmie reticulum (ER) and nuclear envelope cisternae is described in detail. The results demonstrate structural homology between plant and animal annulate lamellae and are compatible with, though do not prove, the view that annulate lamcllar cisternae may originate as a degenerative form of endoplasmic retieulum.
Electron microscopic spread preparations of oocyte nucleoli (lampbrush stage) of various amphibians are quantitatively evaluated and the length distributions of repeat-, matrix-, and spacer-units along the rRNA cistron containing axes are given. The correlation of the matrix unit data with the gel electrophoretic pattern of labelled nuclear RNA from the same oocytes is examined. The mean value of the matrix unit corresponds fairly well to a 2.6 million D peak of pre-rRNA but the distribution of both matrix units and labelled pre-rRNAs shows an asymmetrical heterogeneity indicating the existence of some larger primary transcription products of rDNA. Novel structural aspects are described in the spacer regions which suggest that transcription does also take place in DNP regions between the matrix units. A special "prelude piece" coding for approx. 0.5 million D of RNA is frequently visualized in the spacer segments at the beginning of a matrix unit. Possible artifacts resulting from the preparation, the relative congruence between the data obtained using both methods, and the functional meaning of the findings are discussed against the background of current concepts of structural organization and transcription products of nucleolar DNA.
Segregation of the nucleolar components is described in the differentiated nucleus of the generative cell in the growing Clivia and Lilium pollen tubes. This finding of a natural nucleolar segregation is discussed against the background of current views of the correlations of nucleolar morphology and transcriptional activity.
No abstract available
No abstract available
The influenza virus H1N1 (the A/USSR/90/77 strain) that reappeared in 1977 after the H1N1 influenza viruses had disappeared from the human population, is compared with the A/FM/1/47 and the A/FW/1/50 influenza viruses by the method of oligonucleotide mapping of individual segments of the viral RNAs. Seven genes of the A/USSR/90/77 virus appear to be very similar to the corresponding genes of the A/FW/1/50 virus, whereas the gene coding for the M protein displays considerable homology to the corresponding gene of the A/FM/1/47 virus. The data demonstrate that the A/USSR/90/77 strain is a recombinant virus.
Barley stripe mosaic virus (BSMV) RNA which was previously reported to contain poly(A) sequences (Agranovsky et al., 1978) can be specifically esterified with tyrosine in vitro in the presence of an aminoacyl-tRNA synthetase fraction from wheat embryos. All the three RNA components of the BSMV strain with a three-component genome (Norwich) and both RNA components of a two-component strain (Russian) can be tyrosylated. The poly(A)-containing (bound to oligo(dT)-cellulose) and poly(A)-deficient(not bound to oligo(dT)-cellulose) fractions of BSMV RNA display a similar amino acidaccepting ability. The nucleotide sequence which accepts tyrosine is coupled with the intact genomic polyadenylated BSMV RNA. The viral RNA isolated after sucrose density gradient centrifugation under drastic denaturing conditions retains its aminoacylating activity, which suggests that this activity is not due to the presence in a BSMV RNA preparation of a tyrosine tRNA associated with BSMV RNA. Inhibition of aminoacylation of the 3’-oxidized (treated with sodium metaperiodate) BSMV RNA suggests that the tyrosine-accepting structure is localized at the 3’ terminus of BSMV RNA molecules. It is shown that segments of different lengths obtained upon random fragmentation can be tyrosylated. The 3’-terminal (tyrosine-accepting) poly(A)+ segments can be isolated. The shortest segments of viral RNA capable of being aminoacylated [i.e., containing both tRNA-like structure and poly(A)] consists of approximately 150-200 nucleotides. The analysis of the oligonucleotides derived from individual BSMV RNA components labeled with 32P at the 3’ end revealed two types of 3’-terminal sequences different from poly(A). It is suggested that a poly(A) sequence is intercalated between a 3’-terminal tyrosineaccepting structure and the 5’-terminal portion of poly(A)+ BSMV RNA.