The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA a...The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA and CD45RO phenotypes of lymphocytes were 4eter-mined by indirect immunofluorescence technique. The percentage of CD25, CD45RA and CD45ROpositive lymphocytes was 38.3%±17.3%, 46.0% 15.1%, and 52.6%±14.1% respectively after incu-bation with PHA (5 μ±/ml) for 72 hours. However, there were 58.0%±12.5%, CD25, 64.1% ± 12.4%,CD45RA, and 74.0%±8.0%, CD45RO positive cells in the presence of Rg, ( 1μg/ml) along with PHA(5 μg/ml) over the sanie period of incubation. A significant increase was induced by Rgi (P<0.05).The activities of PTK in the cytoplasm and membrane of lymphocytes were measured by ELISAmcthod after incubation with PHA or PHA+Rg1. The absorbance value of PTK activity in cytoplasmafter 72 hr incubation was 0. 120±0.020 in PHA group, but 0. 1 38±0.015 in PHA+Rg1 group. In thelymphocyte membrane, it was 0.374± 0.060 in PHA group and 0.403 ± 0.008 in PHA+Rg1 group(P<0.001). These results showed that Rgi significantly arid simultaneously increased both the PT Kactivity and the expression of phenotype of lymphocytes.展开更多
Wnts are a large family of growth factors that mediate essential biological processes like embryogenesis, morpho- genesis and organogenesis. These proteins also play a role in oncogenesis, and they regulate apoptosis ...Wnts are a large family of growth factors that mediate essential biological processes like embryogenesis, morpho- genesis and organogenesis. These proteins also play a role in oncogenesis, and they regulate apoptosis in many tissues. Wnts bind to a membrane receptor complex comprised of a frizzled (FZD) G-protein-coupled receptor and a low-density lipoprotein (LDL) receptor-related protein (LRP). The formation of this ligand-receptor complex initiates a number of signaling cascades that include the canonical/beta-catenin pathway as well as several noncanonical pathways. In recent years, canonical Wnt signaling has been reported to play a significant role in the control of bone formation. Clinical studies have found that mutations in LRP-5 are associated with reduced bone mineral density (BMD) and fractures. Investigations of knockout and transgenic mouse models of Wnt pathway components have shown that canonical Wnt signaling modulates most aspects ofosteoblast physiology including proliferation, differentiation, function and apoptosis. Transgenic mice expressing a gain of function mutant of LRP-5 in bone, or mice lacking the Wnt antagonist secreted frizzled-related protein-l, exhibit elevated BMD and suppressed osteoblast apoptosis. In addition, preclinical studies with pharmacologic compounds such as those that inhibit glycogen synthase kinase-3β support the importance of the canonical Wnt pathway in modulation of bone formation and osteoblast apoptosis.展开更多
Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and p...Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25±0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.展开更多
Metabotropic glutamate receptors are expressed at excitatory synapses and control synaptic transmission in mammalian brain. These receptors are involved in numerous patho-physiological functions. However, little is kn...Metabotropic glutamate receptors are expressed at excitatory synapses and control synaptic transmission in mammalian brain. These receptors are involved in numerous patho-physiological functions. However, little is known about the molecular determinants responsible for their intracellular transport and membrane targeting. Here we investigated the nature of the molecular motor and adaptor protein responsible for trafficking and membrane localization of the group I metabotropic glutamate mGlu1 postsynaptic receptor in cultured hippocampal neurons. In proteomic studies, we identified the synaptosome-associated protein 23 (SNAP23) and the molecular motor Kif5 kinesin as proteins interacting with mGlu1 receptor. We showed that SNAP23, but not Kif5, directly interacts with mGlu1 receptor carboxyl terminus. Using a recombination approach to impair or enhance the interaction between SNAP23 and KifS, we found that the SNAP23-Kif5 complex controls the trafficking of mGlu1 receptor along microtubules. Additional fluorescence recovery after cleavage experiments allowed us to identify a role of the complex in the receptor cell surface targeting. In conclusion, our study indicates that along dendritic processes Kif5-SNAP23 complex contributes to proper mGlu1 receptor trafficking and cell surface expression.展开更多
Plants are exposed to numerous potential pathogenic microbes. To counter the threat, plants have evolved diverse patternrecognition receptors(PRRs), which are receptor kinases(RKs) and receptor proteins(RPs) specializ...Plants are exposed to numerous potential pathogenic microbes. To counter the threat, plants have evolved diverse patternrecognition receptors(PRRs), which are receptor kinases(RKs) and receptor proteins(RPs) specialized to detect conserved pathogen/microbe-associated molecular patterns(PAMPs/MAMPs). Although only a handful of RKs and RPs are known PRRs,they belong to the receptor-like kinase(RLK) and receptor-like protein(RLP) superfamilies that undergo lineage-specific expansion, suggesting that many of these RLKs and RLPs are potential PRRs. Analyses of existing PRRs have uncovered ligand-induced RLK-RK or RLK-RP oligomerization as a common mechanism for immune activation. PRRs can recruit additional components to form dynamic receptor complexes, which mediate specific cellular responses. Detailed analyses of these components are shedding light on molecular mechanisms underlying the regulation of PRR activity and downstream signaling.展开更多
Juvenile hormone(JH) and 20-hydroxyecdysone(20 E) coordinately regulate development and metamorphosis in insects. Two JH intracellular receptors, methoprene-tolerant(Met) and germ-cell expressed(Gce), have been identi...Juvenile hormone(JH) and 20-hydroxyecdysone(20 E) coordinately regulate development and metamorphosis in insects. Two JH intracellular receptors, methoprene-tolerant(Met) and germ-cell expressed(Gce), have been identified in the fruit fly Drosophila melanogaster. To investigate JH membrane signaling pathway without the interference from JH intracellular signaling, we characterized phosphoproteome profiles of the Met gce double mutant in the absence or presence of JH in both chronic and acute phases.Functioning through a potential receptor tyrosine kinase and phospholipase C pathway, JH membrane signaling activated protein kinase C(PKC) which phosphorylated ultraspiracle(USP) at Ser35, the PKC phosphorylation site required for the maximal action of 20 E through its nuclear receptor complex Ec RUSP. The usp;mutant, in which Ser was replaced with Ala at position 35 by genome editing, showed decreased expression of Halloween genes that are responsible for ecdysone biosynthesis and thus attenuated 20 E signaling that delayed developmental timing. The usp;mutant also showed lower Yorkie activity that reduced body size. Altogether, JH membrane signaling phosphorylates USP at Ser35 and thus potentiates 20 E action that regulates the normal fly development. This study helps better understand the complex JH signaling network.展开更多
文摘The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA and CD45RO phenotypes of lymphocytes were 4eter-mined by indirect immunofluorescence technique. The percentage of CD25, CD45RA and CD45ROpositive lymphocytes was 38.3%±17.3%, 46.0% 15.1%, and 52.6%±14.1% respectively after incu-bation with PHA (5 μ±/ml) for 72 hours. However, there were 58.0%±12.5%, CD25, 64.1% ± 12.4%,CD45RA, and 74.0%±8.0%, CD45RO positive cells in the presence of Rg, ( 1μg/ml) along with PHA(5 μg/ml) over the sanie period of incubation. A significant increase was induced by Rgi (P<0.05).The activities of PTK in the cytoplasm and membrane of lymphocytes were measured by ELISAmcthod after incubation with PHA or PHA+Rg1. The absorbance value of PTK activity in cytoplasmafter 72 hr incubation was 0. 120±0.020 in PHA group, but 0. 1 38±0.015 in PHA+Rg1 group. In thelymphocyte membrane, it was 0.374± 0.060 in PHA group and 0.403 ± 0.008 in PHA+Rg1 group(P<0.001). These results showed that Rgi significantly arid simultaneously increased both the PT Kactivity and the expression of phenotype of lymphocytes.
文摘Wnts are a large family of growth factors that mediate essential biological processes like embryogenesis, morpho- genesis and organogenesis. These proteins also play a role in oncogenesis, and they regulate apoptosis in many tissues. Wnts bind to a membrane receptor complex comprised of a frizzled (FZD) G-protein-coupled receptor and a low-density lipoprotein (LDL) receptor-related protein (LRP). The formation of this ligand-receptor complex initiates a number of signaling cascades that include the canonical/beta-catenin pathway as well as several noncanonical pathways. In recent years, canonical Wnt signaling has been reported to play a significant role in the control of bone formation. Clinical studies have found that mutations in LRP-5 are associated with reduced bone mineral density (BMD) and fractures. Investigations of knockout and transgenic mouse models of Wnt pathway components have shown that canonical Wnt signaling modulates most aspects ofosteoblast physiology including proliferation, differentiation, function and apoptosis. Transgenic mice expressing a gain of function mutant of LRP-5 in bone, or mice lacking the Wnt antagonist secreted frizzled-related protein-l, exhibit elevated BMD and suppressed osteoblast apoptosis. In addition, preclinical studies with pharmacologic compounds such as those that inhibit glycogen synthase kinase-3β support the importance of the canonical Wnt pathway in modulation of bone formation and osteoblast apoptosis.
文摘Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25±0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.
文摘Metabotropic glutamate receptors are expressed at excitatory synapses and control synaptic transmission in mammalian brain. These receptors are involved in numerous patho-physiological functions. However, little is known about the molecular determinants responsible for their intracellular transport and membrane targeting. Here we investigated the nature of the molecular motor and adaptor protein responsible for trafficking and membrane localization of the group I metabotropic glutamate mGlu1 postsynaptic receptor in cultured hippocampal neurons. In proteomic studies, we identified the synaptosome-associated protein 23 (SNAP23) and the molecular motor Kif5 kinesin as proteins interacting with mGlu1 receptor. We showed that SNAP23, but not Kif5, directly interacts with mGlu1 receptor carboxyl terminus. Using a recombination approach to impair or enhance the interaction between SNAP23 and KifS, we found that the SNAP23-Kif5 complex controls the trafficking of mGlu1 receptor along microtubules. Additional fluorescence recovery after cleavage experiments allowed us to identify a role of the complex in the receptor cell surface targeting. In conclusion, our study indicates that along dendritic processes Kif5-SNAP23 complex contributes to proper mGlu1 receptor trafficking and cell surface expression.
基金supported by Chinese Ministry of Science and Technology(2015CB910201)Chinese Academy of Sciences Strategic Priority Research Program(XDB11020200)
文摘Plants are exposed to numerous potential pathogenic microbes. To counter the threat, plants have evolved diverse patternrecognition receptors(PRRs), which are receptor kinases(RKs) and receptor proteins(RPs) specialized to detect conserved pathogen/microbe-associated molecular patterns(PAMPs/MAMPs). Although only a handful of RKs and RPs are known PRRs,they belong to the receptor-like kinase(RLK) and receptor-like protein(RLP) superfamilies that undergo lineage-specific expansion, suggesting that many of these RLKs and RLPs are potential PRRs. Analyses of existing PRRs have uncovered ligand-induced RLK-RK or RLK-RP oligomerization as a common mechanism for immune activation. PRRs can recruit additional components to form dynamic receptor complexes, which mediate specific cellular responses. Detailed analyses of these components are shedding light on molecular mechanisms underlying the regulation of PRR activity and downstream signaling.
基金supported by the National Natural Science Foundation of China(31620103917 31970459 32070441 31702054 and 31930014)the Shenzhen Science and Technology Program(20180411143628272)the Natural Science Foundation of Guangdong Province(2019A1515011899)。
文摘Juvenile hormone(JH) and 20-hydroxyecdysone(20 E) coordinately regulate development and metamorphosis in insects. Two JH intracellular receptors, methoprene-tolerant(Met) and germ-cell expressed(Gce), have been identified in the fruit fly Drosophila melanogaster. To investigate JH membrane signaling pathway without the interference from JH intracellular signaling, we characterized phosphoproteome profiles of the Met gce double mutant in the absence or presence of JH in both chronic and acute phases.Functioning through a potential receptor tyrosine kinase and phospholipase C pathway, JH membrane signaling activated protein kinase C(PKC) which phosphorylated ultraspiracle(USP) at Ser35, the PKC phosphorylation site required for the maximal action of 20 E through its nuclear receptor complex Ec RUSP. The usp;mutant, in which Ser was replaced with Ala at position 35 by genome editing, showed decreased expression of Halloween genes that are responsible for ecdysone biosynthesis and thus attenuated 20 E signaling that delayed developmental timing. The usp;mutant also showed lower Yorkie activity that reduced body size. Altogether, JH membrane signaling phosphorylates USP at Ser35 and thus potentiates 20 E action that regulates the normal fly development. This study helps better understand the complex JH signaling network.