The Experts below are selected from a list of 71340 Experts worldwide ranked by ideXlab platform
Jean Marie Briantais - One of the best experts on this subject based on the ideXlab platform.
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Light-harvesting chlorophyll a-b Complex Requirement for regulation of Photosystem II photochemistry by non-photochemical quenching.
Photosynthesis Research, 1994Co-Authors: Jean Marie BriantaisAbstract:Recently, it has been suggested (Horton et al. 1992) that aggregation of the light-harvesting a-b Complex (LHC II) in vitro reflects the processes which occur in vivo during fluorescence induction and related to the major non-photochemical quenching (qE). Therefore the Requirement of this chlorophyll a-b containing protein Complex to produce qN was investigated by comparison of two barley mutants either lacking (chlorina f2) or depressed (chlorina104) in LHC II to the wild-type and pea leaves submitted to intermittent light (IL) and during their greening in continuous light.
H Huq - One of the best experts on this subject based on the ideXlab platform.
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the escherichia coli adenylyl cyclase Complex Requirement of pts proteins for stimulation by nucleotides
Biochemistry, 1995Co-Authors: Alan Peterkofsky, Yeongjae Seok, Niranjana D Amin, Roopa Thapar, Sandra Y Lee, Rachel E Klevit, E B Waygood, J W Anderson, James M Gruschus, H HuqAbstract:GTP, as well as other nucleoside triphosphates, stimulates the activity of Escherichia coli adenylyl cyclase in permeable cells; the stimulatory effect is lost when the cells are disrupted by passage through a French pressure cell. These data suggested that the allosteric regulation by GTP of adenylyl cyclase activity requires an interaction of the enzyme with other protein factors. Strains deleted for genes encoding proteins of the phosphoeno1pyruvate:sugar phosphotransferase system (PTS) failed to show an activity stimulation by GTP. With a view to localizing the site of interaction of GTP with the adenylyl cyclase Complex, a variety of studies using purified PTS proteins were performed using the photoaffinity labeling reagent, 8-azidoGTP. These studies showed that 8-azidoGTP bound specifically to HPr. A species specificity study showed that the photoaffinity reagent labeled E. coli HPr but not HPr proteins from Mycoplasma capricolum or Bacillus subtilis. A variety of site-directed mutations of E. coli HPr were evaluated for interaction with GTP by photoaffinity labeling as well as by nuclear magnetic resonance; the results of these studies indicate that the lysine residues at positions 24 and 27, serine-46, the threonine at position 36, and the aspartate at position 69 are important for the binding of GTP to HPr. Molecular modeling has been used to formulate a model for the binding of GTP to HPr involving electrostatic interaction of the phosphate groups of the nucleotide with the side chains of lysine residues 27 and 45 and serine-43, interaction of the sugar with serine-46, and interaction of the base with lysine-24. From these data, it is hypothesized that the binding of GTP to HPr is required for the GTP-dependent stimulation of the activity of the adenylyl cyclase Complex.
Tatsuo Fukagawa - One of the best experts on this subject based on the ideXlab platform.
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The CENP-O Complex Requirement varies among different cell types
Chromosome Research, 2014Co-Authors: Naoko Kagawa, Tetsuya Hori, Yuko Hoki, Osamu Hosoya, Kimiko Tsutsui, Yumiko Saga, Takashi Sado, Tatsuo FukagawaAbstract:CENP-U (CENP-50) is a component of the CENP-O Complex, which includes CENP-O, CENP-P, CENP-Q, CENP-R, and CENP-U and is constitutively localized at kinetochores throughout the cell cycle in vertebrates. Although CENP-U deficiency results in some mitotic defects in chicken DT40 cells, CENP-U-deficient chicken DT40 cells are viable. To examine the functional roles of CENP-U in an organism-dependent context, we generated CENP-U-deficient mice. The CENP-U-deficient mice died during early embryogenesis (approximately E7.5). Thus, conditional CENP-U-deficient mouse ES cells were generated to analyze CENP-U-deficient phenotypes at the cell level. When CENP-U was disrupted in the mouse ES cells, all CENP-O Complex proteins disappeared from kinetochores. In contrast, other kinetochore proteins were recruited in CENP-U-deficient mouse ES cells as CENP-U-deficient DT40 cells. However, the CENP-U-deficient ES cells died after exhibiting abnormal mitotic behavior. Although CENP-U was essential for cell viability during mouse early embryogenesis, CENP-U-deficient mouse embryonic fibroblast cells were viable, similar to the DT40 cells. Thus, although both DT40 and ES cells with CENP-U deficiency have similar mitotic defects, cellular responses to mitotic defects vary among different cell types.
Manajit Hayerhartl - One of the best experts on this subject based on the ideXlab platform.
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Complex chaperone dependence of rubisco biogenesis
Biochemistry, 2018Co-Authors: Robert H Wilson, Manajit HayerhartlAbstract:Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), a ∼530 kDa Complex of 8 large (RbcL) and 8 small subunits (RbcS), mediates the fixation of atmospheric CO2 into usable sugars during photosynthesis. Despite its fundamental role, Rubisco is a remarkably inefficient enzyme and thus is produced by plants in huge amounts. It has long been a key target for bioengineering with the goal to increase crop yields. However, such efforts have been hampered by the Complex Requirement of Rubisco biogenesis for molecular chaperones. Recent studies have identified an array of auxiliary factors needed for the folding and assembly of the Rubisco subunits. The folding of plant RbcL subunits is mediated by the cylindrical chloroplast chaperonin, Cpn60, and its cofactor Cpn20. Folded RbcL requires a number of additional Rubisco specific assembly chaperones, including RbcX, Rubisco accumulation factors 1 (Raf1) and 2 (Raf2), and the Bundle sheath defective-2 (BSD2), to mediate the assembly of the RbcL8 intermediate co...
Junhao Mao - One of the best experts on this subject based on the ideXlab platform.
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abstract b06 Complex Requirement of yap and taz in gastrointestinal development and tumorigenesis
Molecular Cancer Research, 2016Co-Authors: Jennifer L Cotton, Randy L Johnson, Junhao MaoAbstract:YAP and TAZ are the major intracellular mediators of Hippo signaling in mammals; however, the precise function of YAP/TAZ in gastrointestinal development and tumorigenesis remains poorly understood. By specific removal of YAP/TAZ from the developing endoderm and gastrointestinal tract, we find that YAP/TAZ are dispensable for Wnt signal transduction and normal gastrointestinal epithelial differentiation, but act as the direct TCF4 targets and downstream effectors during epithelial transformation. Surprisingly, our loss- and gain-of-function genetic analyses identify an essential role for YAP/TAZ in the gastrointestinal mesenchyme as a molecular switch to coordinate growth and differentiation. We find that YAP/TAZ are required for the expansion of the primitive progenitor populations critical for mesenchymal growth. However, persistent YAP activation inhibits the induction of the smooth muscle lineage, and YAP/TAZ down-regulation during later development is essential for Hedgehog signaling-induced differentiation of smooth muscle cells. Taken together, our studies uncover a Complex Requirement of YAP/TAZ in the gastrointestinal tract and demonstrate the functional interplays among key signaling pathways during gastrointestinal development and tumorigenesis. Citation Format: Jennifer L. Cotton, Qi Li, Lifang Ma, Tony Ip, Randy Johnson, Junhao Mao. Complex Requirement of YAP and TAZ in gastrointestinal development and tumorigenesis. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr B06.