Search results for "InAs"

Revisiting the pH-gated conformational switch on the activities of HisKA-family histidine kinases

2020

13 páginas, 6 figuras, 3 tablas

Addition of thiols to the double bond of dipeptide C-terminal dehydroalanine as a source of new inhibitors of cathepsin C.

2017

Addition of thiols to double bond of glycyl-dehydroalanine and phenyl-dehydroalanine esters provided micromolar inhibitors of cathepsin C. The structure-activity studies indicated that dipeptides containing N-terminal phenylalanine exhibit higher affinity towards the enzyme. A series of C-terminal S-substituted cysteines are responsible for varying interaction with S1 binding pocket of cathepsin C. Depending on diastereomer these compounds most likely act as slowly reacting substrates or competitive inhibitors. This was proved by TLC analysis of the medium in which interaction of methyl (S)-phenylalanyl-(R,S)-(S-adamantyl)cysteinate (7i) with the enzyme was studied. Molecular modeling enabl…

Sensory domain contraction in histidine kinase CitA triggers transmembrane signaling in the membrane-bound sensor

2017

Bacteria use membrane-integral sensor histidine kinases (HK) to perceive stimuli and transduce signals from the environment to the cytosol. Information on how the signal is transmitted across the membrane by HKs is still scarce. Combining both liquid- and solid-state NMR, we demonstrate that structural rearrangements in the extracytoplasmic, citrate-sensing Per-Arnt-Sim (PAS) domain of HK CitA are identical for the isolated domain in solution and in a longer construct containing the membrane-embedded HK and lacking only the kinase core. We show that upon citrate binding, the PAS domain contracts, resulting in a shortening of the C-terminal β-strand. We demonstrate that this contraction of t…

CitA (citrate) and DcuS (C4-dicarboxylate) sensor kinases in thermophilic Geobacillus kaustophilus and Geobacillus thermodenitrificans

2015

The thermophilic Geobacillus thermodenitrificans and Geobacillus kaustophilus are able to use citrate or C4-dicarboxylates like fumarate or succinate as the substrates for growth. The genomes of the sequenced Geobacillus strains (nine strains) each encoded a two-component system of the CitA family. The sensor kinase of G. thermodenitrificans (termed CitAGt) was able to replace CitA of Escherichia coli (CitAEc) in a heterologous complementation assay restoring expression of the CitAEc-dependent citC-lacZ reporter gene and anaerobic growth on citrate. Complementation was specific for citrate. The sensor kinase of G. kaustophilus (termed DcuSGk) was able to replace DcuSEc of E. coli. It respon…

In silico discovery of substituted pyrido[2,3-d]pyrimidines and pentamidine-like compounds with biological activity in myotonic dystrophy models

2016

Myotonic dystrophy type 1 (DM1) is a rare multisystemic disorder associated with an expansion of CUG repeats in mutant DMPK (dystrophia myotonica protein kinase) transcripts; the main effect of these expansions is the induction of pre-mRNA splicing defects by sequestering muscleblind-like family proteins (e.g. MBNL1). Disruption of the CUG repeats and the MBNL1 protein complex has been established as the best therapeutic approach for DM1, hence two main strategies have been proposed: targeted degradation of mutant DMPK transcripts and the development of CUG-binding molecules that prevent MBNL1 sequestration. Herein, suitable CUG-binding small molecules were selected using in silico approach…

Specific role of N-methyl-D-aspartate (NMDA) receptor in elastin-derived VGVAPG peptide-dependent calcium homeostasis in mouse cortical astrocytes in…

2019

AbstractUnder physiological and pathological conditions, elastin is degraded to produce elastin-derived peptides (EDPs). EDPs are detected in the healthy human brain, and its concentration significantly increases after ischemic stroke. Both elastin and EDPs contains replications of the soluble VGVAPG hexapeptide, which has a broad range of biological activities. Effects of VGVAPG action are mainly mediated by elastin-binding protein (EBP), which is alternatively spliced, enzymatically inactive form of the GLB1 gene. This study was conducted to elucidate the activation and role of the N-methyl-D-aspartate receptor (NMDAR) in elastin-derived VGVAPG peptide-dependent calcium homeostasis in mou…

2016

Regulatory T cells (Treg) are essential for T cell homeostasis and maintenance of peripheral tolerance. They prevent activation of auto-reactive T effector cells (Teff) in the context of autoimmunity and allergy. Otherwise, Treg also inhibit effective immune responses against tumors. Besides a number of Treg-associated molecules such as Foxp3, CTLA-4 or GARP, known to play critical roles in Treg differentiation, activation and function, the involvement of additional regulatory elements is suggested. Herein, kinase activities seem to play an important role in Treg fine tuning. Nevertheless, our knowledge regarding the complex intracellular signaling pathways controlling phenotype and functio…

2016

Asthma is characterized by periodic episodes of bronchoconstriction and reversible airway obstruction; these symptoms are attributable to a number of factors including increased mass and reactivity of bronchial smooth muscle and extracellular matrix (ECM) in asthmatic airways. Literature has suggested changes in cell responses and signaling can be elicited via modulation of mechanical stress acting upon them, potentially affecting the microenvironment of the cell. In this study, we hypothesized that mechanical strain directly affects the (myo)fibroblast phenotype in asthma. Therefore, we characterized responses of bronchial fibroblasts, from 6 normal and 11 asthmatic non-smoking volunteers,…

β1-Integrin– and K(V)1.3 channel–dependent signaling stimulates glutamate release from Th17 cells

2020

Although the impact of Th17 cells on autoimmunity is undisputable, their pathogenic effector mechanism is still enigmatic. We discovered soluble N-ethylmaleimide–sensitive factor attachment receptor (SNARE) complex proteins in Th17 cells that enable a vesicular glutamate release pathway that induces local intracytoplasmic calcium release and subsequent damage in neurons. This pathway is glutamine dependent and triggered by binding of β1-integrin to vascular cell adhesion molecule 1 (VCAM-1) on neurons in the inflammatory context. Glutamate secretion could be blocked by inhibiting either glutaminase or K(V)1.3 channels, which are known to be linked to integrin expression and highly expressed…

Influence of middle-distance running on muscular micro RNAs

2018

A specific subset of micro RNAs (miRs), including miR-133 and miR-206, is specifically expressed in muscle tissue, so that they are currently defined as muscular miRs (myomiRs). To further elucidate the role of myomiRs in muscle biology, we measured miR-133a and miR-206 in plasma of 28 middle-age recreational athletes. The study population consisted of 28 middle aged, recreation athletes (11 women and 17 men; mean age, 46 years) who completed a 21.1 km, half-marathon. The plasma concentration of miR-133a and miR-206, the serum concentration of creatine kinase (CK) and high-sensitivity (HS) cardiac troponin T (cTnT), as well as capillary lactate, were measured before and immediately after th…