Search results for "Protein S"

Role of Redox Signaling and Inflammation in Skeletal Muscle Adaptations to Training

2016

The inflammatory response to exercise-induced muscle damage has been extensively described. Exercise has important modulatory effects on immune function. These effects are mediated by diverse factors including pro-inflammatory cytokines, classical stress hormones, and hemodynamic effects leading to cell redistribution. As has been reported regarding oxidative stress, inflammation can have both detrimental and beneficial effects in skeletal muscle. In this review we will address the role of inflammation on protein metabolism in skeletal muscle. Specifically, we will review studies showing that treatment with cyclooxygenase-inhibiting drugs modulate the protein synthesis response to one bout …

Structural Basis of the High Affinity Interaction between the Alphavirus Nonstructural Protein-3 (nsP3) and the SH3 Domain of Amphiphysin-2

2016

We show that a peptide from Chikungunya virus nsP3 protein spanning residues 1728–1744 binds the amphiphysin-2 (BIN1) Src homology-3 (SH3) domain with an unusually high affinity (Kd 24 nM). Our NMR solution complex structure together with isothermal titration calorimetry data on several related viral and cellular peptide ligands reveal that this exceptional affinity originates from interactions between multiple basic residues in the target peptide and the extensive negatively charged binding surface of amphiphysin-2 SH3. Remarkably, these arginines show no fixed conformation in the complex structure, indicating that a transient or fluctuating polyelectrostatic interaction accounts for this …

STRIPAK Members Orchestrate Hippo and Insulin Receptor Signaling to Promote Neural Stem Cell Reactivation

2019

Summary Adult stem cells reactivate from quiescence to maintain tissue homeostasis and in response to injury. How the underlying regulatory signals are integrated is largely unknown. Drosophila neural stem cells (NSCs) also leave quiescence to generate adult neurons and glia, a process that is dependent on Hippo signaling inhibition and activation of the insulin-like receptor (InR)/PI3K/Akt cascade. We performed a transcriptome analysis of individual quiescent and reactivating NSCs harvested directly from Drosophila brains and identified the conserved STRIPAK complex members mob4, cka, and PP2A (microtubule star, mts). We show that PP2A/Mts phosphatase, with its regulatory subunit Widerbors…

Antiprotozoal and cysteine proteases inhibitory activity of dipeptidyl enoates

2018

A family of dipeptidyl enoates has been prepared and tested against the parasitic cysteine proteases rhodesain, cruzain and falcipain-2 related to sleeping sickness, Chagas disease and malaria, respectively. They have also been tested against human cathepsins B and L1 for selectivity. Dipeptidyl enoates resulted to be irreversible inhibitors of these enzymes. Some of the members of the family are very potent inhibitors of parasitic cysteine proteases displaying k2nd (M−1s−1) values of seven orders of magnitude. In vivo antiprotozoal testing was also performed. Inhibitors exhibited IC50 values in the micromolar range against Plasmodium falciparum, Trypanosoma brucei, Trypanosoma cruzi and ev…

alpha 2-COP is involved in early secretory traffic in Arabidopsis and is required for plant growth

2017

[EN] COP (coat protein) I-coated vesicles mediate intra-Golgi transport and retrograde transport from the Golgi to the endoplasmic reticulum. These vesicles form through the action of the small GTPase ADP-ribosylation factor 1 (ARF1) and the COPI heptameric protein complex (coatomer), which consists of seven subunits (alpha-, beta-, beta' -, gamma-, delta-, epsilon- and xi-COP). In contrast to mammals and yeast, several isoforms for coatomer subunits, with the exception of gamma and delta, have been identified in Arabidopsis. To understand the role of COPI proteins in plant biology, we have identified and characterized a loss-of-function mutant of alpha 2-COP, an Arabidopsis alpha-COP isofo…

Structural and Functional Characterization of Autophosphorylation in Bacterial Histidine Kinases

2019

Autophosphorylation of histidine kinases (HK) is the first step for signal transduction in bacterial two-component signalling systems. As HKs dimerize, the His residue is phosphorylated in cis or trans depending on whether the ATP molecule used in the reaction is bound to the same or the neighboring subunit, respectively. The cis or trans autophosphorylation results from an alternative directionality in the connection between helices α1 and α2 in the HK DHp domain, in such a way that α2 could be oriented almost 90° counterclockwise or clockwise with respect to α1. Sequence and length variability of this connection appears to lie behind the different directionality and is implicated in partn…

Characterization of crustacyanin-A2 subunit as a component of the organic matrix of gastroliths from the crayfish Cherax quadricarinatus.

2009

AbstractLike the lobsters, some terrestrial crabs and other crayfishes, the Australian red claw crayfish, Cherax quadricarinatus, elaborates in its stomach wall calcium storage structures called gastroliths. For understanding the cyclic elaboration and stabilization of these amorphous calcified structures, we studied the organic matrix (OM) of these paired biomineralizations. After decalcification with acetic acid, we analysed the proteinaceous components of an acetic acid-insoluble fraction by two-dimensional electrophoresis. Nine spots were digested by trpsin and the tryptic peptides were sequenced by nanoLC-nanoESI-MS/MS mass spectrometry. About 100 peptidic sequences were compared to se…

2019

Mammalian fetuin-A and fetuin-B are abundant serum proteins with pleiotropic functions. Fetuin-B is a highly selective and potent inhibitor of metallopeptidases (MPs) of the astacin family, which includes ovastacin in mammals. By inhibiting ovastacin, fetuin-B is essential for female fertility. The crystal structure of fetuin-B was determined unbound and in complex with archetypal astacin, and it was found that the inhibitor has tandem cystatin-type modules (CY1 and CY2). They are connected by an exposed linker with a rigid, disulfide-linked `CPDCP-trunk', and are followed by a C-terminal region (CTR) with little regular secondary structure. The CPDCP-trunk and a hairpin of CY2 form a bipar…

Detecting Protein Aggregation on Cells Surface: Concanavalin A Oligomers Formation

2009

A number of neurodegenerative diseases involve protein aggregation and amyloid formation. Recently evidence has emerged indicating small-transient prefibrillar oligomers as the primary pathogenic agents. Noteworthy, strict analogies exist between the behaviour of cells in culture treated with misfolded non-pathogenic proteins and in pathologic conditions, this instance together with the observation that the oligomers and fibrils are characterised by common structural features suggest that common mechanisms for cytotoxicity could exists and have to be perused in common interactions involved in aggregation.We here report an experimental study on ConcanavalinA (ConA) aggregation and its effect…

Visualizing Human Protein‐Protein Interactions and Subcellular Localizations on Cell Images Through CellMap

2020

Visualizing protein data remains a challenging and stimulating task. Useful and intuitive visualization tools may help advance biomolecular and medical research; unintuitive tools may bar important breakthroughs. This protocol describes two use cases for the CellMap (http://cellmap.protein.properties) web tool. The tool allows researchers to visualize human protein-protein interaction data constrained by protein subcellular localizations. In the simplest form, proteins are visualized on cell images that also show protein-protein interactions (PPIs) through lines (edges) connecting the proteins across the compartments. At a glance, this simultaneously highlights spatial constraints that prot…