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21.
The actin domain of Gardner-Rasheed feline sarcoma virus inhibits kinase and transforming activities. 总被引:1,自引:0,他引:1 下载免费PDF全文
The transforming gene product, P70gag-actin-fgr, of Gardner-Rasheed feline sarcoma virus (GR-FeSV) is a single polypeptide composed of regions derived from cellular and viral genes. Gamma actin and c-fgr genes are the two known cellular components of the GR-FeSV genome. In the present study, sequences representing each cell-derived gene were deleted and the resulting constructs were tested for transforming activity by transfection of NIH 3T3 cells. Constructs lacking a portion of the c-fgr proto-oncogene failed to induce focus formation, demonstrating the essential nature of this component for GR-FeSV oncogenic activity. In contrast, the construct lacking the actin domain was more active than GR-FeSV DNA in transformation assays. Protein specified by the actin deletion mutant possessed a 2.4-fold greater specific protein-tyrosine kinase activity compared with that of the wild-type gene product. Furthermore, the actin domain had no detectable effect on the ability of the fgr kinase to associate with cytoskeleton or to phosphorylate unique cellular proteins on tyrosine. Our findings demonstrate that the actin domain inhibits focus formation and impairs protein-tyrosine kinase activity. 相似文献
22.
Shigeki Shibahara Yasushi Tomita Miki Yoshizawa Koushi Shibata Hachiro Tagami 《Pigment cell & melanoma research》1990,3(Z2):90-95
The pigment cell-specific gene, located at the brown (b)-locus in mouse, encodes the protein that determines the type of melanin synthesized. This protein is known as tyrosinase-related protein, but here we tentatively term it b-locus protein to avoid confusions with the related sequence cross-hybridizing to the tyrosinase gene. In order to identify the mutation at the b-locus, we have cloned and characterized the b-locus protein gene of BALB/c mouse (b/b, c/c). The gene is about 18 kb long and organized into 8 exons and 7 introns. Sequence analysis of the b-locus protein gene reveals four base changes within the protein-coding regions: two missense mutations and two silent mutations. Two missense mutations result in the Cys to Tyr substitution at position 86 (codon 110) and the Arg to His substitution at position 302 (codon 326) of a b-locus protein molecule. Using allele-specific amplification, we confirmed that these missense mutations are actually present in the genomic DNA of two b-mutant strains examined, BALB/c and DBA/2 (b/b, C/C) mice, suggesting that these mutations are specific for the mutant mice at the b-locus. Moreover, we are able to show that the b-locus protein containing Tyr 86 is not reactive with the anti-b-locus protein monoclonal antibody, TMH-1, in transient expression assays. 相似文献
23.
Structure, function and expression of a murine homeobox protein AREC3, a homologue of Drosophila sine oculis gene product, and implication in development. 总被引:4,自引:0,他引:4 下载免费PDF全文
The cDNA clones encoding ARE(Na,K-ATPase alpha1 subunit gene regulatory element) binding protein AREC3 were isolated from myoblast C2C12 cells and mouse skeletal muscle cDNA library. At least four alternatively spliced forms of AREC3 cDNA were identified. Sequence analysis indicates that AREC3 has an extensive homology with the Drosophila sine oculis gene product required for development of the entire visual system [Cheyette et al.(1994) Neuron 12, 977-996]. The homologous region including a homeodomain is required for specific DNA binding to ARE. A transactivation domain was identified in the C-terminal part of the AREC3 by reporter gene assays using GAL4-AREC3 fusion protein constructs. Immunohistochemistry revealed that AREC3 localized to the nucleus and cytoplasm of myoblast C2C12 cells, and the production of AREC3 is augmented during muscle differentiation. Western blot analysis indicated that the 115 kDa form of AREC3 protein is increased in the cytoplasmic extract, and the 67kDa form is increased both in nuclear and cytoplasmic extracts of C2C12 cells during muscle differentiation. 相似文献
24.
Summary Silica glass-entrapped lipase was prepared by the sol-gel method using tetramethoxysilane, and its esterification activity in n-hexane was examined for isoamylbutyrate formation. The hydrogel preparation containing a large amount of water exhibited enough activity. Although the activity of xerogel-entrapped lipase drastically decreased probably due to shrinkage of the gel matrix, the lyophilized gel retained much higher activity than the air-dried gel. 相似文献
25.
Yoshiyuki Kawakami Ichiro Ueno Tsutomu Katsuyama Ken'ichi Furihata Hideki Matsumoto 《Microbiology and immunology》1994,38(11):891-895
Epidemiological typing, based on restriction fragment length polymorphism (RFLP) by pulsed-field gel electrophoresis (PFGE), was attempted for the 38 clinical isolates of Moraxella catarrhalis obtained at Shinshu University Hospital during the years 1987 and 1993. Digestion with SmaI or NotI generated well separable, 12 to 5 genomic DNA fragments ranging from 1,000 kb to 30 kb and the strains could be classified into 14 or 13 types, respectively. The electrophoretic profile differed with the strain in most of them and was hence useful to distinguish the each strain. Investigation for their RFLP have, however, suggested that majority of them, including the type strain ATCC25238, may have derived from a common ancestor. 相似文献
26.
27.
Noriyuki Suka Yoshinobu Shinohara Yasushi Saitoh Hisato Saitoh Kohei Ohtomo Masahiko Harata Edward Shpigelman Shigeki Mizuno 《Genetica》1993,88(2-3):93-105
About 65% of DNA in the chicken W chromosome has been shown to consist ofXhoI andEcoRI family repetitive sequences. These sequences showed remarkable delay in the electrophoretic mobility at low temperature
on a polyacrylamide gel. Three dimensional structures of the 0.7-kbXhoI and the 1.2-kbEcoRI family repeating units were estimated to be irregular solenoids using a computer program based on wedge angles of all the
16 dinucleotide steps. Fluorescencein situ hybridization demonstrated that these two family sequences were localized in a major heterochromatic body in an interphase
nucleus. Incorporation of bromodeoxyuridine into the W chromosome in the synchronous culture of MSB-1 cells occurred about
1 h later than the peak of S phase. The chromatin structure formed alongXhoI andEcoRI family sequences was suggested to be different from the total chromatin or chromatin containing the β-actin gene sequence
in that the linker DNA lengths of the former were significantly longer. Fractionation of theHaeIII-digested MSB-1 nuclei yielded a chromatin fraction in whichXhoI family sequences were partially enriched. Several DNA-binding proteins showing higher affinity for theXhoI family sequence were present in this fraction. 相似文献
28.
Tadashi Kawakami Naoshi Hikawa Tatsumi Kusakabe Masato Kano Yoko Bandou Hideki Gotoh Toshifumi Takenaka 《Developmental neurobiology》1993,24(5):545-551
The inhibitory effect of capsaicin on axoplasmic transport in cultured dorsal root ganglion cells was analyzed by video-enhanced contrast microscopy. Capsaicin inhibited particle transports in a dose-dependent manner, irrespective of the diameter of axons. The effect of capsaicin was reversible at low concentrations. Capsaicin affected both the anterograde and retrograde transport. Large organelles were more sensitive to capsaicin than small ones in the retrograde transport. An experiment using calcium-sensitive dye, Fura 2, indicated that capsaicin raised the intraneuronal free calcium concentration preceding the inhibition of the transport. Electron microscopy revealed that microtubules and neurofilaments are disorganized and disoriented by capsaicin. We reached a conclusion that capsaicin inhibits fast axoplasmic transport of both anterograde and retrograde directions in all types of somatosensory neurons in culture by disorganizing intraaxonal cytoskeletal structures, through the elevated intracellular Ca2+ concentration. © 1993 John Wiley & Sons, Inc. 相似文献
29.
SSCP analysis of pig mitochondrial DNA D-loop region polymorphism 总被引:10,自引:0,他引:10
The sequence polymorphism that occurs in the mitochondrial DNA (mtDNA) displacement (D)-loop region is useful as a cytoplasmic DNA marker. We cloned the mtDNA D-loop regions of five breeds of pig by polymerase chain reaction (PCR) and determined their sequences. The sequence diversities in D-loop regions among five breeds of pig were located in the starting area of heavy-strand replication. From these sequences, we designed primers for PCR-mediated single-strand conformation polymorphism (PCR-SSCP) analysis that amplified the most polymorphic 227 bp fragment of the D-loop region. The results of PCR-SSCP analysis clearly showed that four types of polymorphism (A to D) are found in Landrace (A), Large White (A, B), Duroc (A), Göttingen miniature pig (B) and Meishan (C, D). The same polymorphisms were also detected from each porcine embryo by this method. Our results show that PCR-SSCP analysis is useful in detecting polymorphisms in the D-loop region of pigs and pig embryos. 相似文献
30.