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961.
Kamimura K Koyama T Habuchi H Ueda R Masu M Kimata K Nakato H 《The Journal of cell biology》2006,174(6):773-778
Specific sulfation sequence of heparan sulfate (HS) contributes to the selective interaction between HS and various proteins in vitro. To clarify the in vivo importance of HS fine structures, we characterized the functions of the Drosophila HS 2-O and 6-O sulfotransferase (Hs2st and Hs6st) genes in FGF-mediated tracheal formation. We found that mutations in Hs2st or Hs6st had unexpectedly little effect on tracheal morphogenesis. Structural analysis of mutant HS revealed not only a loss of corresponding sulfation, but also a compensatory increase of sulfation at other positions, which maintains the level of HS total charge. The restricted phenotypes of Hsst mutants are ascribed to this compensation because FGF signaling is strongly disrupted by Hs2st; Hs6st double mutation, or by overexpression of 6-O sulfatase, an extracellular enzyme which removes 6-O sulfate groups without increasing 2-O sulfation. These findings suggest that the overall sulfation level is more important than strictly defined HS fine structures for FGF signaling in some developmental contexts. 相似文献
962.
Takeaki Ikeuchi Mizuki Yasumoto Teisuke Takita Keisuke Tanaka Masashi Kusubata Osamu Hayashida Shunji Hattori Kimihiko Mizutani Bunzo Mikami Kiyoshi Yasukawa 《The Journal of biological chemistry》2022,298(8)
Collagenase from the gram-negative bacterium Grimontia hollisae strain 1706B (Ghcol) degrades collagen more efficiently even than clostridial collagenase, the most widely used industrial collagenase. However, the structural determinants facilitating this efficiency are unclear. Here, we report the crystal structures of ligand-free and Gly-Pro-hydroxyproline (Hyp)-complexed Ghcol at 2.2 and 2.4 Å resolution, respectively. These structures revealed that the activator and peptidase domains in Ghcol form a saddle-shaped structure with one zinc ion and four calcium ions. In addition, the activator domain comprises two homologous subdomains, whereas zinc-bound water was observed in the ligand-free Ghcol. In the ligand-complexed Ghcol, we found two Gly-Pro-Hyp molecules, each bind at the active site and at two surfaces on the duplicate subdomains of the activator domain facing the active site, and the nucleophilic water is replaced by the carboxyl oxygen of Hyp at the P1 position. Furthermore, all Gly-Pro-Hyp molecules bound to Ghcol have almost the same conformation as Pro-Pro-Gly motif in model collagen (Pro-Pro-Gly)10, suggesting these three sites contribute to the unwinding of the collagen triple helix. A comparison of activities revealed that Ghcol exhibits broader substrate specificity than clostridial collagenase at the P2 and P2′ positions, which may be attributed to the larger space available for substrate binding at the S2 and S2′ sites in Ghcol. Analysis of variants of three active-site Tyr residues revealed that mutation of Tyr564 affected catalysis, whereas mutation of Tyr476 or Tyr555 affected substrate recognition. These results provide insights into the substrate specificity and mechanism of G. hollisae collagenase. 相似文献
963.
Naftopidil reduced the proliferation of lung fibroblasts and bleomycin‐induced lung fibrosis in mice
Hirokazu Urushiyama Yasuhiro Terasaki Shinya Nagasaka Nariaki Kokuho Youko Endo Mika Terasaki Shinobu Kunugi Kosuke Makita Hideaki Isago Keisuke Hosoki Kunihiko Souma Takashi Ishii Hirotaka Matsuzaki Yoshihisa Hiraishi Yu Mikami Satoshi Noguchi Hiroyuki Tamiya Akihisa Mitani Yasuhiro Yamauchi Akira Shimizu Takahide Nagase 《Journal of cellular and molecular medicine》2019,23(5):3563-3571
Naftopidil, an α‐1 adrenoceptor antagonist with few adverse effects, is prescribed for prostate hyperplasia. Naftopidil inhibits prostate fibroblast proliferation; however, its effects on lung fibroblasts and fibrosis remain largely unknown. Two normal and one idiopathic pulmonary fibrosis human lung fibroblast lines were cultured with various naftopidil concentrations with or without phenoxybenzamine, an irreversible α‐1 adrenoceptor inhibitor. We examined the incorporation of 5‐bromo‐2?‐deoxyuridine into DNA and lactic acid dehydrogenase release by enzyme‐linked immunosorbent assay, cell cycle analysis by flow cytometry, scratch wound‐healing assay, and mRNA expressions of type IV collagen and α‐smooth muscle actin by polymerase chain reaction. Effects of naftopidil on bleomycin‐induced lung fibrosis in mice were evaluated using histology, micro‐computed tomography, and surfactant protein‐D levels in serum. Naftopidil, dose‐dependently but independently of phenoxybenzamine, inhibited 5‐bromo‐2?‐deoxyuridine incorporation in lung fibroblasts. Naftopidil induced G1 cell cycle arrest, but lactic acid dehydrogenase release and migration ability of lung fibroblasts were unaffected. Naftopidil decreased mRNA expressions of type IV collagen and α‐smooth muscle actin in one normal lung fibroblast line. Histological and micro‐computed tomography examination revealed that naftopidil attenuated lung fibrosis and decreased serum surfactant protein‐D levels in bleomycin‐induced lung fibrosis in mice. In conclusion, naftopidil may have therapeutic effects on lung fibrosis. 相似文献
964.
965.
966.
Recombination-Deficient Mutants of an Extreme Thermophile, Thermus thermophilus 总被引:6,自引:1,他引:5
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Tohru Takada Satoshi Akanuma Takashi Kotsuka Masatada Tamakoshi Akihiko Yamagishi Tairo Oshima 《Applied microbiology》1993,59(8):2737-2739
Recombination-deficient strains of the extreme thermophile Thermus thermophilus have been prepared from a leucine-isoleucine mutant strain (NM6). The availability of such recombination-deficient thermophilic bacterial strains may provide especially good hosts for work with plasmid vectors. 相似文献
967.
A physical map of the sulfur-dependent archaebacterium Sulfolobus acidocaldarius 7 chromosome. 总被引:4,自引:4,他引:0
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A chromosomal map of the sulfur-dependent thermoacidophilic archaebacterium Sulfolobus acidocaldarius 7 was constructed with four restriction enzymes: NotI, BssHII, RsrII, and EagI. The map indicated that the chromosome is a single circular DNA of 2,760 +/- 20 kb (mean +/- standard error of the mean). rRNA genes were also mapped. They were located at one site in the genome. 相似文献
968.
Identification of Cytoplasmic and Nuclear Low-Molecular-Weight Heat-Shock Proteins in Tomato Fruit 总被引:1,自引:0,他引:1
Kato Shigeaki; Yamagishi Kozo; Tatsuzawa Fumi; Suzuki Kazuo; Takano Saburo; Eguchi Masahiro; Hasegawa Tadao 《Plant & cell physiology》1993,34(2):367-370
Several low-molecular-weight heat-shock proteins were detectedby two-dimensional electro-phoresis in substantial amounts inboth nuclear and cytosolic extracts of tomato fruit. (Received September 16, 1992; Accepted November 27, 1992) 相似文献
969.
Purification and Characterization of Phosphoribulokinase from the Cyanobacterium Synechococcus PCC7942 总被引:1,自引:0,他引:1
Wadano Akira; Kamata Yoichi; Iwaki Toshio; Nishikawa Keisuke; Hirahashi Tomohiro 《Plant & cell physiology》1995,36(7):1381-1385
Phosphoribulokinase (PRK) was purified to electrophoretic homogeneityfrom Synechococcus PCC7942 with high specific activity. Molecularmasses of the native enzyme and its subunit were 178 and 42kDa, respectively. Cys-17 and Cys-38 were conserved in the cyanobacterialPRK, but 18 amino acid residues between them were missing amongthe 40 residues found in higher plant PRKs. (Received February 1, 1995; Accepted July 27, 1995) 相似文献
970.
Two types of interstitial cells have been demonstrated in close association in the deep muscular plexus of rat small intestine, by electron microscopy. Cells of the first type are characterized by a fibroblastic ultrastructure, i.e. a well-developed granular endoplasmic reticulum, Golgi apparatus and absence of the basal lamina. They form a few small gap junctions with the circular muscle cells and show close contact with axon terminals containing many synaptic vesicles. They may play a role in conducting electrical signals in the muscle tissue. Cells of the second type are characterized by many large gap junctions that interconnect with each other and with the circular muscle cells. Their cytoplasm is rich in cell organells, including mitochondria, granular endoplasmic reticulum and Golgi apparatus. They show some resemblance to the smooth muscle cells and have an incomplete basal lamina, caveolae and subsurface cisterns. However, they do not contain an organized contractile apparatus, although many intermediate filaments are present in their processes. They also show close contacts with axon terminals containing synaptic vesicles. These gap-junction-rich cells may be regular components of the intestinal tract and may be involved in the pacemaking activity of intestinal movement. 相似文献