Complex Patterns of Histidine, Hydroxylated Amino Acids and the GxxxG Motif Mediate High-affinity Transmembrane Domain Interactions

2009 ◽  
Vol 385 (3) ◽  
pp. 912-923 ◽  
Author(s):  
Jana R. Herrmann ◽  
Johanna C. Panitz ◽  
Stephanie Unterreitmeier ◽  
Angelika Fuchs ◽  
Dmitrij Frishman ◽  
...  
Keyword(s):  
Amino Acids ◽  
Transmembrane Domain ◽  
High Affinity ◽  
Gxxxg Motif ◽  
Domain Interactions ◽  
Complex Patterns

scholarly journals Transmembrane Domain Interactions Control Biological Functions of Neuropilin-1

2008 ◽  
Vol 19 (2) ◽  
pp. 646-654 ◽  
Author(s):  
Lise Roth ◽  
Cécile Nasarre ◽  
Sylvie Dirrig-Grosch ◽  
Dominique Aunis ◽  
Gérard Crémel ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
Inhibitory Effect ◽  
Transmembrane Segment ◽  
Vegf Signaling ◽  
Receptor Complexes ◽  
Gxxxg Motif ◽  
Neuropilin 1 ◽  
Domain Interactions ◽  
Shed Light

Neuropilin-1 (NRP1) is a transmembrane receptor playing a pivotal role in the control of semaphorins and VEGF signaling pathways. The exact mechanism controlling semaphorin receptor complex formation is unknown. A structural analysis and modeling of NRP1 revealed a putative dimerization GxxxG motif potentially important for NRP1 dimerization and oligomerization. Our data show that this motif mediates the dimerization of the transmembrane domain of NRP1 as demonstrated by a dimerization assay (ToxLuc assay) performed in natural membrane and FRET analysis. A synthetic peptide derived from the transmembrane segment of NRP1 abolished the inhibitory effect of Sema3A. This effect depends on the capacity of the peptide to interfere with NRP1 dimerization and the formation of oligomeric complexes. Mutation of the GxxxG dimerization motif in the transmembrane domain of NRP1 confirmed its biological importance for Sema3A signaling. Overall, our results shed light on an essential step required for semaphorin signaling and provide novel evidence for the crucial role of transmembrane domain of bitopic protein containing GxxxG motif in the formation of receptor complexes that are a prerequisite for cell signaling.

Structural and functional interactions between FXYD5 and the Na+-K+-ATPase

2007 ◽  
Vol 293 (6) ◽  
pp. F1818-F1826 ◽  
Author(s):  
Irina Lubarski ◽  
Steven J. D. Karlish ◽  
Haim Garty
Keyword(s):  
Amino Acids ◽  
Transmembrane Domain ◽  
Xenopus Laevis Oocytes ◽  
Kidney Tubules ◽  
Α Subunit ◽  
Functional Interactions ◽  
High Affinity ◽  
Metastatic Cells ◽  
Structural Interactions ◽  
Affinity Interaction

FXYD5 is a member of a family of tissue-specific regulators of the Na+-K+-ATPase expressed in kidney tubules. Previously, we have shown that FXYD5 interacts with the αβ-subunits of the Na+-K+-ATPase and increases its Vmax (Lubarski I, Pihakaski-Maunsbach K, Karlish SJ, Maunsbach AB, Garty H. J Biol Chem 280: 37717–37724, 2005). The current study further characterizes structural interaction and structure-function relationships of FXYD5. FXYD5/FXYD4 chimeras expressed in Xenopus laevis oocytes have been used to demonstrate that both the high-affinity association with the pump and the increase in Vmax are mediated by the transmembrane domain of FXYD5. Several amino acids that participate in the high-affinity interaction between FXYD5 and the α-subunit of the Na+-K+-ATPase have been identified. The data suggest that different FXYD proteins interact similarly with the Na+-K+-ATPase and their transmembrane domains play a key role in both the structural interactions and functional effects. Other experiments have identified at least one splice variant of FXYD5 with 10 additional amino acids at the COOH terminus, suggesting the possibility of other functional effects not mediated by the transmembrane domain. FXYD5 could be specifically bound to wheat germ agglutinin beads, indicating that it is glycosylated. However, unlike previous findings in metastatic cells, such glycosylation does not evoke a large increase in the size of the protein expressed in native epithelia and X. laevis oocytes.

Molecular docking studies of tea (Thea sinensis Linn.) polyphenols inhibition pattern with Rat P-glycoprotein

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Babar Ali ◽  
Qazi Mohammad Sajid Jamal ◽  
Showkat R. Mir ◽  
Saiba Shams ◽  
Mohammad Amjad Kamal
Keyword(s):  
Amino Acids ◽  
Molecular Docking ◽  
Binding Energy ◽  
Oral Administration ◽  
Docking Studies ◽  
Vital Role ◽  
Glycoprotein P ◽  
High Affinity ◽  
P Glycoprotein ◽  
Inhibition Pattern

AbstractSince 3000 B.C., evergreen plant Thea sinensis (Theaceae) is used both as a social and medicinal beverage. Leaves of T. sinensis contain amino acids, vitamins, caffeine, polysaccharides and polyphenols. Most of the natural medicinal actions of tea are due to the availability and abundance of polyphenols mainly catechins. It has also been stated that some catechins were absorbed more rapidly than other compounds after the oral administration of tea and could increase the bio-enhancing activities of anticancer drugs by inhibiting P-glycoprotein (P-gp). The results of the molecular docking showed that polyphenols bind easily to the active P-gp site. All compounds exhibited fluctuating binding affinity ranged from −11.67 to −8.36 kcal/mol. Observed binding energy required for theaflavin to bind to P-gp was lowest (−11.67 kcal/mol). The obtained data that supports all the selected polyphenols inhibited P-gp and therefore may enhance the bioavailability of drugs. This study may play a vital role in finding hotspots in P-gp and eventually may be proved useful in designing compounds with high affinity and specificity to the protein.

scholarly journals Human Rev1 relies on insert-2 to promote selective binding and accurate replication of stabilized G-quadruplex motifs

2021 ◽  
Author(s):  
Amit Ketkar ◽  
Lane Smith ◽  
Callie Johnson ◽  
Alyssa Richey ◽  
Makayla Berry ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mutation Frequency ◽  
Control Sequence ◽  
Wild Type ◽  
Binding Properties ◽  
High Affinity ◽  
G4 Dna ◽  
G Quadruplex ◽  
Forward Mutagenesis

Abstract We previously reported that human Rev1 (hRev1) bound to a parallel-stranded G-quadruplex (G4) from the c-MYC promoter with high affinity. We have extended those results to include other G4 motifs, finding that hRev1 exhibited stronger affinity for parallel-stranded G4 than either anti-parallel or hybrid folds. Amino acids in the αE helix of insert-2 were identified as being important for G4 binding. Mutating E466 and Y470 to alanine selectively perturbed G4 binding affinity. The E466K mutant restored wild-type G4 binding properties. Using a forward mutagenesis assay, we discovered that loss of hRev1 increased G4 mutation frequency >200-fold compared to the control sequence. Base substitutions and deletions occurred around and within the G4 motif. Pyridostatin (PDS) exacerbated this effect, as the mutation frequency increased >700-fold over control and deletions upstream of the G4 site more than doubled. Mutagenic replication of G4 DNA (±PDS) was partially rescued by wild-type and E466K hRev1. The E466A or Y470A mutants failed to suppress the PDS-induced increase in G4 mutation frequency. These findings have implications for the role of insert-2, a motif conserved in vertebrates but not yeast or plants, in Rev1-mediated suppression of mutagenesis during G4 replication.

Interactions of mouse glycophorin A with the dRTA-related mutant G719D of the mouse Cl–/HCO3– exchanger Ae1This paper is one of a selection of papers published in a Special Issue entitled CSBMCB 53rd Annual Meeting — Membrane Proteins in Health and Disease, and has undergone the Journal’s usual peer review process.

2011 ◽  
Vol 89 (2) ◽  
pp. 224-235 ◽  
Author(s):  
Andrew K. Stewart ◽  
Fouad T. Chebib ◽  
Syed W. Akbar ◽  
Maria J. Salas ◽  
Rajan A. Sonik ◽  
...  
Keyword(s):  
Amino Acids ◽  
Transmembrane Domain ◽  
Peer Review Process ◽  
Surface Expression ◽  
Amino Acid Sequences ◽  
Glycophorin A ◽  
Specific Expression ◽  
Health And Disease ◽  
Renal Tubular

The AE1 mutation G701D, associated with recessive distal renal tubular acidosis (dRTA), produces only minimal erythroid phenotype, reflecting erythroid-specific expression of stimulatory AE1 subunit glycophorin A (GPA). GPA transgene expression could theoretically treat recessive dRTA in patients and in mice expressing cognate Ae1 mutation G719D. However, human (h) GPA and mouse (m) Gpa amino acid sequences are widely divergent, and mGpa function in vitro has not been investigated. We therefore studied in Xenopus oocytes the effects of coexpressed mGpa and hGPA on anion transport by erythroid (e) and kidney (k) isoforms of wild-type mAe1 (meAe1, mkAe1) and of mAe1 mutant G719D. Coexpression of hGPA or mGpa enhanced the function of meAe1 and mkAe1 and rescued the nonfunctional meAe1 and mkAe1 G719D mutants through increased surface expression. Progressive N-terminal truncation studies revealed a role for meAe1 amino acids 22–28 in GPA-responsiveness of meAe1 G719D. MouseN-cyto/humanTMD and humanN-cyto/mouseTMD kAE1 chimeras were active and GPA-responsive. In contrast, whereas chimera mkAe1N-cyto/hkAE1 G701DTMD was GPA-responsive, chimera hkAE1N-cyto/mkAe1 G719DTMD was GPA-insensitive. Moreover, whereas the isolated transmembrane domain (TMD) of hAE1 G701D was GPA-responsive, that of mAe1 G719D was GPA-insensitive. Thus, mGpa increases surface expression and activity of meAe1 and mkAe1. However, the G719D mutation renders certain mAe1 mutant constructs GPA-unresponsive and highlights a role for erythroid-specific meAe1 amino acids 22–28 in GPA-responsiveness.

Cloning and characterization of a human brain Na + -independent transporter for small neutral amino acids that transports d -serine with high affinity

2000 ◽  
Vol 287 (3) ◽  
pp. 231-235 ◽  
Author(s):  
Jun Nakauchi ◽  
Hirotaka Matsuo ◽  
Do Kyung Kim ◽  
Akiteru Goto ◽  
Arthit Chairoungdua ◽  
...  
Keyword(s):  
Amino Acids ◽  
Human Brain ◽  
Neutral Amino Acids ◽  
High Affinity

scholarly journals Expression cloning of a human renal cDNA that induces high affinity transport of L-cystine shared with dibasic amino acids in Xenopus oocytes

1993 ◽  
Vol 268 (20) ◽  
pp. 14842-14849
Author(s):  
J. Bertran ◽  
A. Werner ◽  
J. Chillarón ◽  
V. Nunes ◽  
J. Biber ◽  
...  
Keyword(s):  
Amino Acids ◽  
Xenopus Oocytes ◽  
Expression Cloning ◽  
High Affinity ◽  
Dibasic Amino Acids
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