The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Jose I Carreto - One of the best experts on this subject based on the ideXlab platform.
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palythine Threonine a major novel mycosporine like amino acid maa isolated from the hermatypic coral pocillopora capitata
Journal of Photochemistry and Photobiology B-biology, 2009Co-Authors: Mario O Carignan, Diogo Oliveirasilva, Pio Colepicolo, Karina Helena Morais Cardozo, Jose I CarretoAbstract:Abstract Using a high-resolution reverse-phase liquid chromatography method we found that the tissues of the hermatypic coral Pocillopora capitata (collected in Santiago Bay, Mexico) contain a high diversity of primary and secondary mycosporine-like amino acids (MAAs) typical of some reef-building coral species: mycosporine–glycine, shinorine, porphyra-334, mycosporine–methylamine–serine, mycosporine–methylamine–Threonine, palythine–serine, palythine and one additional novel predominant MAA, with an absorbance maximum of 320 nm. Here we document the isolation and characterization of this novel MAA from the coral P. capitata. Using low multi-stage mass analyses of deuterated and non deuterated compounds, high-resolution mass analyses (Time of Flight, TOF) and other techniques, this novel compound was characterized as palythine–Threonine. Palythine–Threonine was also present in high concentrations in the corals Pocillopora eydouxi and Stylophora pistillata indicating a wider distribution of this MAA among reef-building corals. From structural considerations we suggest that palythine–Threonine is formed by decarboxylation of porphyra-334 followed by demethylation of mycosporine–methylamine–Threonine.
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Palythine–Threonine, a major novel mycosporine-like amino acid (MAA) isolated from the hermatypic coral Pocillopora capitata
Journal of Photochemistry and Photobiology B-biology, 2008Co-Authors: Mario O Carignan, Pio Colepicolo, Diogo Oliveira-silva, Karina Helena Morais Cardozo, Jose I CarretoAbstract:Abstract Using a high-resolution reverse-phase liquid chromatography method we found that the tissues of the hermatypic coral Pocillopora capitata (collected in Santiago Bay, Mexico) contain a high diversity of primary and secondary mycosporine-like amino acids (MAAs) typical of some reef-building coral species: mycosporine–glycine, shinorine, porphyra-334, mycosporine–methylamine–serine, mycosporine–methylamine–Threonine, palythine–serine, palythine and one additional novel predominant MAA, with an absorbance maximum of 320 nm. Here we document the isolation and characterization of this novel MAA from the coral P. capitata. Using low multi-stage mass analyses of deuterated and non deuterated compounds, high-resolution mass analyses (Time of Flight, TOF) and other techniques, this novel compound was characterized as palythine–Threonine. Palythine–Threonine was also present in high concentrations in the corals Pocillopora eydouxi and Stylophora pistillata indicating a wider distribution of this MAA among reef-building corals. From structural considerations we suggest that palythine–Threonine is formed by decarboxylation of porphyra-334 followed by demethylation of mycosporine–methylamine–Threonine.
Anna Greka - One of the best experts on this subject based on the ideXlab platform.
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synaptopodin is a coincidence detector of tyrosine versus serine Threonine phosphorylation for the modulation of rho protein crosstalk in podocytes
Journal of The American Society of Nephrology, 2017Co-Authors: Lisa Buvall, Hanna Wallentin, Jonas Sieber, Svetlana Andreeva, Hoon Young Choi, Peter Mundel, Anna GrekaAbstract:Tyrosine and serine/Threonine signal-transduction pathways influence many aspects of cell behavior, including the spatial and temporal regulation of the actin cytoskeleton. However, little is known about how input from diverse tyrosine and serine/Threonine kinases is integrated to control Rho protein crosstalk and actin remodeling, which are critically important in podocyte health and disease. Here we unveil the proteolytically-regulated, actin organizing protein synaptopodin as a coincidence detector of tyrosine versus serine/Threonine phosphorylation. We show that serine/Threonine and tyrosine kinases duel for synaptopodin stability versus degradation. EGFR/Src-mediated tyrosine phosphorylation of synaptopodin in podocytes promotes binding to the serine/Threonine phosphatase calcineurin. This leads to the loss of 14–3-3 binding, resulting in synaptopodin degradation, Vav2 activation, enhanced Rac1 signaling, and ultimate loss of stress fibers. Our studies reveal how synaptopodin, a single proteolytically-controlled protein, integrates antagonistic tyrosine versus serine/Threonine phosphorylation events for the dynamic control of the actin cytoskeleton in podocytes.
A Mufson - One of the best experts on this subject based on the ideXlab platform.
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Serine/Threonine phosphorylation in cytokine signal transduction
Leukemia, 2000Co-Authors: Ja Mccubrey, V Duronio, A MufsonAbstract:Over the past decade, the involvement of tyrosine kinases in signal transduction pathways evoked by cytokines has been intensively investigated. Only relatively recently have the roles of serine/Threonine kinases in cytokine-induced signal transduction and anti-apoptotic pathways been examined. Cytokine receptors without intrinsic kinase activity such as interleukin-3 (IL-3), granulocyte–macrophage colony-stimulating factor (GM-CSF) and the interferons were thought to transmit their regulatory signals primarily by the receptor-associated Jak family of tyrosine kinases. This family of tyrosine kinases activates STAT transcription factors, which subsequently transduced their signals into the nucleus to modulate gene expression. Cytokine receptors with intrinsic tyrosine kinase activity such as c-Kit were initially thought to transduce their signals independently of serine/Threonine kinase cascades. Recently, both of these types of receptor signaling pathways have been shown to interact with serine/Threonine kinase pathways as maximal activation of these tyrosine kinase regulated cascades involve serine/Threonine phosphorylation modulated by, for example MAP kinases. A common intermediate pathway initiating from cytokine receptors is the Ras/Raf/MEK/ERK (MAPK) cascade, which can result in the phosphorylation and activation of additional downstream kinases and transcription factors such as p90^Rsk, CREB, Elk and Egr-1. Serine/Threonine phosphorylation is also involved in the regulation of the apoptosis-controlling Bcl-2 protein, as certain phosphorylation events induced by cytokines such as IL-3 are anti-apoptotic, whereas other phosphorylation events triggered by chemotherapeutic drugs such as Paclitaxel are associated with cell death. Serine/Threonine phosphorylation is implicated in the etiology of certain human cancers as constitutive serine phosphorylation of STATs 1 and 3 is observed in chronic lymphocytic leukemia and can be inhibited by the chemotherapeutic drug fludarabine. Serine/Threonine phosphorylation also plays a role in the etiology of immunodeficiencies. Activated STAT5 proteins are detected in reduced levels in lymphocytes recovered from HIV-infected individuals and immunocompromised mice. Serine/Threonine phosphorylation may be an important target of certain chemotherapeutic drugs which recognize the activated proteins. This meeting report and mini-review will discuss the interactions of serine/Threonine kinases with signal transduction and apoptotic molecules and how some of these pathways can be controlled by chemotherapeutic drugs.
Mario O Carignan - One of the best experts on this subject based on the ideXlab platform.
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palythine Threonine a major novel mycosporine like amino acid maa isolated from the hermatypic coral pocillopora capitata
Journal of Photochemistry and Photobiology B-biology, 2009Co-Authors: Mario O Carignan, Diogo Oliveirasilva, Pio Colepicolo, Karina Helena Morais Cardozo, Jose I CarretoAbstract:Abstract Using a high-resolution reverse-phase liquid chromatography method we found that the tissues of the hermatypic coral Pocillopora capitata (collected in Santiago Bay, Mexico) contain a high diversity of primary and secondary mycosporine-like amino acids (MAAs) typical of some reef-building coral species: mycosporine–glycine, shinorine, porphyra-334, mycosporine–methylamine–serine, mycosporine–methylamine–Threonine, palythine–serine, palythine and one additional novel predominant MAA, with an absorbance maximum of 320 nm. Here we document the isolation and characterization of this novel MAA from the coral P. capitata. Using low multi-stage mass analyses of deuterated and non deuterated compounds, high-resolution mass analyses (Time of Flight, TOF) and other techniques, this novel compound was characterized as palythine–Threonine. Palythine–Threonine was also present in high concentrations in the corals Pocillopora eydouxi and Stylophora pistillata indicating a wider distribution of this MAA among reef-building corals. From structural considerations we suggest that palythine–Threonine is formed by decarboxylation of porphyra-334 followed by demethylation of mycosporine–methylamine–Threonine.
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Palythine–Threonine, a major novel mycosporine-like amino acid (MAA) isolated from the hermatypic coral Pocillopora capitata
Journal of Photochemistry and Photobiology B-biology, 2008Co-Authors: Mario O Carignan, Pio Colepicolo, Diogo Oliveira-silva, Karina Helena Morais Cardozo, Jose I CarretoAbstract:Abstract Using a high-resolution reverse-phase liquid chromatography method we found that the tissues of the hermatypic coral Pocillopora capitata (collected in Santiago Bay, Mexico) contain a high diversity of primary and secondary mycosporine-like amino acids (MAAs) typical of some reef-building coral species: mycosporine–glycine, shinorine, porphyra-334, mycosporine–methylamine–serine, mycosporine–methylamine–Threonine, palythine–serine, palythine and one additional novel predominant MAA, with an absorbance maximum of 320 nm. Here we document the isolation and characterization of this novel MAA from the coral P. capitata. Using low multi-stage mass analyses of deuterated and non deuterated compounds, high-resolution mass analyses (Time of Flight, TOF) and other techniques, this novel compound was characterized as palythine–Threonine. Palythine–Threonine was also present in high concentrations in the corals Pocillopora eydouxi and Stylophora pistillata indicating a wider distribution of this MAA among reef-building corals. From structural considerations we suggest that palythine–Threonine is formed by decarboxylation of porphyra-334 followed by demethylation of mycosporine–methylamine–Threonine.
Philip Cohen - One of the best experts on this subject based on the ideXlab platform.
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dissection of the protein kinase cascade by which nerve growth factor activates map kinases
Nature, 1991Co-Authors: Nestor Gomez, Philip CohenAbstract:MITOGEN activated protein (MAP) kinases (MAPKs) are a family of protein-serine/Threonine kinases activated as an early intracellular response to a variety of hormones and growth factors1–4. They are unique in requiring both serine/Threonine and tyrosine phosphorylation to become active5 and are the only examples of protein-serine/Threonine kinases activated by tyrosine phosphorylation. Nerve growth factor (NGF) promotes differentiation of phaeochromocytoma (PC12) cells, which respond by conversion within hours from a chromaffin-like to a sympathetic neuron-like phenotype6,7. NGF stimulation of PC 12 cells increases the activity of two protein kinases by > 20-fold within minutes8, both strikingly similar to MAPKs. They are inactivated by either protein-tyrosine phosphatases or the protein-serine/Threonine phosphatase termed protein phosphatase 2A (ref. 8), they activate protein S6 kinase-II (refs 9,10), and they phosphorylate identical Threonine residues on myelin basic protein (our unpublished results) to those phosphorylated by other MAPKs11,12. Immunological data13 indicate that these protein kinases, termed peak-I and peak-II (Fig. la) are probably ERK2 and ERK1, respectively, two widely expressed MAPK isoforms13. Here we identify the 'MAP kinase kinases' (MAPKKs) in PC12 cells which are activated by NGF and report that MAPKKs are dependent on serine/Threonine phosphorylation for activity and promote phosphorylation of serine/Threonine and tyrosine residues on MAPKs.
