scholarly journals Intestinal basolateral lipid substrate transport is linked to chylomicron secretion and is regulated by apoC-III

2019 ◽  
Vol 60 (9) ◽  
pp. 1503-1515 ◽  
Author(s):  
Diana Li ◽  
Cayla N. Rodia ◽  
Zania K. Johnson ◽  
Minkyung Bae ◽  
Angelika Muter ◽  
...  
Keyword(s):  
Substrate Transport ◽  
Lipid Substrate

Substrate Transport for Production at Variable Process Speeds

2018 ◽  
Vol 2018 (1) ◽  
pp. 103-106
Author(s):  
Thomas Oberle ◽  
Christoph Ziegler ◽  
Robert Thieme ◽  
Martin Porschen
Keyword(s):  
Substrate Transport

scholarly journals Evidence for the critical role of transmembrane helices 1 and 7 in substrate transport by human P-glycoprotein (ABCB1)

PLoS ONE ◽  
2018 ◽  
Vol 13 (9) ◽  
pp. e0204693 ◽  
Author(s):  
Andaleeb Sajid ◽  
Sabrina Lusvarghi ◽  
Eduardo E. Chufan ◽  
Suresh V. Ambudkar
Keyword(s):  
Critical Role ◽  
Transmembrane Helices ◽  
Substrate Transport ◽  
P Glycoprotein

scholarly journals Transition of yeast Can1 transporter to the inward-facing state unveils an α-arrestin target sequence promoting its ubiquitylation and endocytosis

2017 ◽  
Vol 28 (21) ◽  
pp. 2819-2832 ◽  
Author(s):  
Christos Gournas ◽  
Elie Saliba ◽  
Eva-Maria Krammer ◽  
Céline Barthelemy ◽  
Martine Prévost ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Control Mechanism ◽  
Molecular Level ◽  
Membrane Transporters ◽  
Signaling Cascades ◽  
Target Sequence ◽  
Target Region ◽  
Substrate Transport ◽  
Common Control ◽  
Amino Acid Permeases

Substrate-transport–elicited endocytosis is a common control mechanism of membrane transporters avoiding excess uptake of external compounds, though poorly understood at the molecular level. In yeast, endocytosis of transporters is triggered by their ubiquitylation mediated by the Rsp5 ubiquitin-ligase, recruited by α-arrestin–family adaptors. We here report that transport-elicited ubiquitylation of the arginine transporter Can1 is promoted by transition to an inward-facing state. This conformational change unveils a region of the N-terminal cytosolic tail targeted by the Art1 α-arrestin, which is activated via the TORC1 kinase complex upon arginine uptake. Can1 mutants altered in the arginine-binding site or a cytosolic tripeptide sequence permanently expose the α-arrestin–targeted region so that Art1 activation via TORC1 is sufficient to trigger their endocytosis. We also provide evidence that substrate-transport elicited endocytosis of other amino acid permeases similarly involves unmasking of a cytosolic Art1-target region coupled to activation of Art1 via TORC1. Our results unravel a mechanism likely involved in regulation of many other transporters by their own substrates. They also support the emerging view that transporter ubiquitylation relies on combinatorial interaction rules such that α-arrestins, stimulated via signaling cascades or in their basal state, recognize transporter regions permanently facing the cytosol or unveiled during transport.

scholarly journals Dependence on pH of substrate binding to a mutant lactose carrier, lacYun, in Escherichia coli. A model for H+/lactose symport

1989 ◽  
Vol 258 (2) ◽  
pp. 389-396 ◽  
Author(s):  
I Yamato ◽  
Y Anraku
Keyword(s):  
Escherichia Coli ◽  
Substrate Binding ◽  
Ph Dependence ◽  
Plasmid Vector ◽  
Binary Complex ◽  
Wild Type ◽  
Transport Reaction ◽  
Substrate Transport ◽  
Vector Pbr322 ◽  
Dissociation Step

The lacYun gene, which encodes a lactose carrier showing the uncoupled phenotype of substrate transport in Escherichia coli [Wilson, Kusch & Kashket (1970) Biochem. Biophys. Res. Commun. 40, 1409-1414], was cloned on a plasmid vector, pBR322. The binding of a substrate, p-nitrophenyl alpha-galactoside, to the lacYun carrier in membranes from the strain harbouring the lacYun clone showed a pH-dependence different from its binding to the wild-type lactose carrier. This finding indicated that the lacYun mutation confers higher affinity for H+ on the carrier, exerting its effect on the less efficient dissociation of substrate inside cells. The result coincides with the proposal [Yamato & Rosenbusch (1983) FEBS Lett. 151, 102-104] that the proton affecting the substrate binding is the coupling proton of the proton/lactose symport reaction, which allows only the ordered mechanism of binding of substrate to an H+-carrier binary complex. From the simplest model of the symport reaction, constructed on the basis of these results, the coupling site of energy in the carrier cycle of the transport reaction can be identified at the substrate-dissociation step inside cells.

Carbon-encapsulated iron nanoparticles used to generate magnetic field and to enhance substrate transport at electrode surface

2012 ◽  
Vol 20 ◽  
pp. 4-6 ◽  
Author(s):  
Anna M. Nowicka ◽  
Agata Kowalczyk ◽  
Michal Bystrzejewski ◽  
Mikolaj Donten ◽  
Zbigniew Stojek
Keyword(s):  
Magnetic Field ◽  
Electrode Surface ◽  
Iron Nanoparticles ◽  
Substrate Transport

scholarly journals Substrate Interaction with the EssC Coupling Protein of the Type VIIb Secretion System

2020 ◽  
Vol 202 (7) ◽  
Author(s):  
Nicole Mietrach ◽  
Diana Damián-Aparicio ◽  
Benjamin Mielich-Süss ◽  
Daniel Lopez ◽  
Sebastian Geibel
Keyword(s):  
Critical Role ◽  
Secretion System ◽  
Effector Proteins ◽  
Resistant Bacteria ◽  
Infection Model ◽  
Atpase Domain ◽  
Bacterial Persistence ◽  
Substrate Transport ◽  
Content Type ◽  
Coupling Protein

ABSTRACT Staphylococcus aureus employs the type VIIb secretion system (T7SSb) to secrete effector proteins that either have antibacterial activities or promote bacterial persistence in mouse infection models. Here, we present the crystal structure of the ATPase domain D3 of the EssC coupling protein from S. aureus USA300_FPR3757, an integral component of the T7SSb complex, resolved at a 1.7-Å resolution. EssC-D3 shares structural homology with FtsK/SpoIII-like ATPase domains of T7SSa and T7SSb and exhibits a conserved pocket on the surface with differential amino acid composition. In T7SSa, substrate EsxB interacts with the D3 domain through this pocket. Here, we identify amino acids in this pocket that are essential for effector protein secretion in the T7SSb. Our results reveal that the adjacent ATPase domain D2 is a substrate binding site on EssC and that substrates bound to D2 require domain D3 for further transport. Point mutations in the Walker B motif of domain D3 have diametric effects on secretion activity, either abolishing or boosting it, pointing to a critical role of domain D3 in the substrate transport. Finally, we identify ATPase domain D3 as a virulence determinant of S. aureus USA300_FPR3757 using an invertebrate in vivo infection model. IMPORTANCE The emergence of antibiotic-resistant bacteria poses a rising problem in antibiotic treatment (S. Boyle-Vavra and R. S. Daum, Lab Invest 87:3–9, 2007, https://doi.org/10.1038/labinvest.3700501). We have used the multidrug-resistant S. aureus USA300_FPR3757 as a model organism to study the T7SSb. Effector proteins of this system have been associated with abscess formation and bacterial persistence in mouse models (M. L. Burts, A. C. DeDent, and D. M. Missiakas, Mol Microbiol 69:736–746, 2008, https://doi.org/10.1111/j.1365-2958.2008.06324.x; M. L. Burts, W. A. Williams, K. DeBord, and D. M. Missiakas, Proc Natl Acad Sci U S A 102:1169–1174, 2005, https://doi.org/10.1073/pnas.0405620102). We determined the structure of the essential ATPase domain D3 of the T7SSb at atomic resolution and validated a surface-exposed pocket as a potential drug target to block secretion. Furthermore, our study provides new mechanistic insights into the T7SSb substrate transport.

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