scholarly journals Trefoil Factor Family (TFF) Modules Are Characteristic Constituents of Separate Mucin Complexes in the Xenopus laevis Integumentary Mucus: In Vitro Binding Studies with FIM-A.1

2020 ◽  
Vol 21 (7) ◽  
pp. 2400 ◽  
Author(s):  
René Stürmer ◽  
Jana Reising ◽  
Werner Hoffmann
Keyword(s):  
Molecular Mass ◽  
Complex I ◽  
Size Exclusion ◽  
Trefoil Factor ◽  
Binding Studies ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Exclusion Chromatography ◽  
Trefoil Factor Family

The skin of the frog Xenopus laeevis is protected from microbial infections by a mucus barrier that contains frog integumentary mucins (FIM)-A.1, FIM-B.1, and FIM-C.1. These gel-forming mucins are synthesized in mucous glands consisting of ordinary mucous cells and one or more cone cells at the gland base. FIM-A.1 and FIM-C.1 are unique because their cysteine-rich domains belong to the trefoil factor family (TFF). Furthermore, FIM-A.1 is unusually short (about 400 amino acid residues). In contrast, FIM-B.1 contains cysteine-rich von Willebrand D (vWD) domains. Here, we separate skin extracts by the use of size exclusion chromatography and analyze the distribution of FIM-A.1 and FIM-C.1. Two mucin complexes were detected, i.e., a high-molecular-mass Complex I, which contains FIM-C.1 and little FIM-A.1, whereas Complex II is of lower molecular mass and contains the bulk of FIM-A.1. We purified FIM-A.1 by a combination of size-exclusion chromatography (SEC) and anion-exchange chromatography and performed first in vitro binding studies with radioactively labeled FIM-A.1. Binding of 125I-labeled FIM-A.1 to the high-molecular-mass Complex I was observed. We hypothesize that the presence of FIM-A.1 in Complex I is likely due to lectin interactions, e.g., with FIM-C.1, creating a complex mucus network.

scholarly journals Different Forms of TFF2, A Lectin of the Human Gastric Mucus Barrier: In Vitro Binding Studies

2019 ◽  
Vol 20 (23) ◽  
pp. 5871 ◽  
Author(s):  
Franziska Heuer ◽  
René Stürmer ◽  
Jörn Heuer ◽  
Thomas Kalinski ◽  
Antje Lemke ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Gastric Mucus ◽  
Binding Studies ◽  
Binding Characteristics ◽  
Duodenal Glands ◽  
Vitro Binding ◽  
Trefoil Factor Family ◽  
Mucus Barrier ◽  
Mass Form

Trefoil factor family 2 (TFF2) and the mucin MUC6 are co-secreted from human gastric and duodenal glands. TFF2 binds MUC6 as a lectin and is a constituent of the gastric mucus. Herein, we investigated human gastric extracts by FPLC and identified mainly high- but also low-molecular-mass forms of TFF2. From the high-molecular-mass forms, TFF2 can be completely released by boiling in SDS or by harsh denaturing extraction. The low-molecular-mass form representing monomeric TFF2 can be washed out in part from gastric mucosa specimens with buffer. Overlay assays with radioactively labeled TFF2 revealed binding to the mucin MUC6 and not MUC5AC. This binding is modulated by Ca2+ and can be blocked by the lectin GSA-II and the monoclonal antibody HIK1083. TFF2 binding was also inhibited by Me-β-Gal, but not the α anomer. Thus, both the α1,4GlcNAc as well as the juxtaperipheral β-galactoside residues of the characteristic GlcNAcα1→4Galβ1→R moiety of human MUC6 are essential for TFF2 binding. Furthermore, there are major differences in the TFF2 binding characteristics when human is compared with the porcine system. Taken together, TFF2 appears to fulfill an important role in stabilizing the inner insoluble gastric mucus barrier layer, particularly by its binding to the mucin MUC6.

IC-P-199: Comparing [3 H]MK-6240 and [3 H]AV-1451(T-807) In In vitro Binding Studies in Brain Tissues

2016 ◽  
Vol 12 ◽  
pp. P144-P144
Author(s):  
Zhizhen Zeng ◽  
Patricia J. Miller ◽  
Brett M. Connolly ◽  
Stacey S. O’Malley ◽  
Idriss Bennacef ◽  
...  
Keyword(s):  
Binding Studies ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Brain Tissues

scholarly journals Lyn Physically Associates With the Erythropoietin Receptor and May Play a Role in Activation of the Stat5 Pathway

Blood ◽  
1998 ◽  
Vol 91 (10) ◽  
pp. 3734-3745 ◽  
Author(s):  
Hiroshi Chin ◽  
Ayako Arai ◽  
Hiroshi Wakao ◽  
Ryuichi Kamiyama ◽  
Nobuyuki Miyasaka ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Kinase Domain ◽  
Sh2 Domain ◽  
Erythropoietin Receptor ◽  
Tyrosine Kinase Domain ◽  
Binding Studies ◽  
In Vitro Binding ◽  
Vitro Binding

Abstract Protein tyrosine phosphorylation plays a crucial role in signaling from the receptor for erythropoietin (Epo), although the Epo receptor (EpoR) lacks the tyrosine kinase domain. We have previously shown that the Jak2 tyrosine kinase couples with the EpoR to transduce a growth signal. In the present study, we demonstrate that Lyn, a Src family tyrosine kinase, physically associates with the EpoR in Epo-dependent hematopoietic cell lines, 32D/EpoR-Wt and F36E. Coexpression experiments in COS7 cells further showed that Lyn induces tyrosine phosphorylation of the EpoR and that both LynA and LynB, alternatively spliced forms of Lyn, bind with the membrane-proximal 91-amino acid region of the EpoR cytoplasmic domain. In vitro binding studies using GST-Lyn fusion proteins further showed that the Src homology (SH)-2 domain of Lyn specifically binds with the tyrosine-phosphorylated EpoR in lysate from Epo-stimulated cells, whereas the tyrosine kinase domain of Lyn binds with the unphosphorylated EpoR. Far-Western blotting and synthetic phosphopeptide competition assays further indicated that the Lyn SH2 domain directly binds to the tyrosine-phosphorylated EpoR, most likely through its interaction with phosphorylated Y-464 or Y-479 in the carboxy-terminal region of the EpoR. In vitro binding studies also demonstrated that the Lyn SH2 domain directly binds to tyrosine-phosphorylated Jak2. In vitro reconstitution experiments in COS7 cells further showed that Lyn induces tyrosine phosphorylation of Stat5, mainly on Y-694, and activates the DNA-binding and transcription-activating abilities of Stat5. In agreement with this, Lyn enhanced the Stat5-dependent transcriptional activation when overexpressed in 32D/EpoR-Wt cells. In addition, Lyn was demonstrated to phosphorylate the EpoR and Stat5 on tyrosines in vitro. These results suggest that Lyn may play a role in activation of the Jak2/Stat5 and other signaling pathways by the EpoR.

scholarly journals Physical and functional interactions between Stat5 and the tyrosine- phosphorylated receptors for erythropoietin and interleukin-3

Blood ◽  
1996 ◽  
Vol 88 (12) ◽  
pp. 4415-4425 ◽  
Author(s):  
H Chin ◽  
N Nakamura ◽  
R Kamiyama ◽  
N Miyasaka ◽  
JN Ihle ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Sh2 Domain ◽  
Binding Studies ◽  
Interleukin 3 ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Docking Sites ◽  
Carboxy Terminal

Erythropoietin (Epo) and interleukin-3 (IL-3) stimulate activation of the Jak2 tyrosine kinase and induce tyrosine phosphorylation and activation of Stat5. In the present study, we have shown that Epo or IL-3 stimulation induces binding of Stat5 to the tyrosine-phosphorylated Epo receptor (EpoR) or IL-3 receptor beta subunit (betaIL3), respectively, in IL-3-dependent 32D cells expressing the EpoR. The binding of Stat5 to these cytokine receptors was shown to be rapid and transient, occurring within 1 minute of stimulation of cells and significantly decreasing after 5 minutes of cell treatment. In vivo binding experiments in COS cells showed that binding of Stat5 to the EpoR was mediated through the Stat5 Src homology 2 (SH2) domain. In vitro binding studies further showed that Stat5, but not other Stats examined, bound specifically to tyrosine-phosphorylated recombinant EpoR fusion proteins. In these in vivo and in vitro binding studies, Stat5 bound, albeit to a lesser degree, to truncated EpoR mutants in which all the intracellular tyrosines except Y-343 were removed. Furthermore, EpoR-derived synthetic phosphotyrosine peptides corresponding to Y-343, Y-401, Y-431, and Y-479 inhibited the in vitro binding of Stat5. When expressed in 32D cells, a mutant EpoR in which all the intracellular tyrosines were removed by carboxy-terminal truncation showed a significantly impaired ability to induce tyrosine phosphorylation of Stat5, particularly at low concentrations of Epo, but exhibited an increased sensitivity to Epo for growth signaling as compared with the wild-type EpoR. These results indicate that Stat5 specifically and transiently binds to the EpoR through the interaction between the Stat5 SH2 domain and specific phosphorylated tyrosines, including Y-343, in the EpoR cytoplasmic domain. It was implied that betaIL3 may also have similar Stat5 docking sites. The Stat5 docking sites in the EpoR were shown to facilitate specific activation of Stat5, which, however, may not be required for the EpoR-mediated growth signaling.

IN VITRO BINDING STUDIES TO EVALUATE THE NFT-SPECIFICITY OF [3H]MK-6240 AND [3H]AV-1451 BINDING IN SUBCORTICAL REGIONS OF THE HUMAN AD BRAIN

2017 ◽  
Vol 13 (7) ◽  
pp. P150-P151 ◽  
Author(s):  
Zhizhen Zeng ◽  
Patricia J. Miller ◽  
Brett M. Connolly ◽  
Stacey S. O’Malley ◽  
Talakad Lohith ◽  
...  
Keyword(s):  
Binding Studies ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Subcortical Regions

[P4-055]: IN VITRO BINDING STUDIES TO EVALUATE THE NFT-SPECIFICITY OF [3 H]MK-6240 AND [3 H]AV-1451 BINDING IN SUBCORTICAL REGIONS OF HUMAN AD BRAIN

2017 ◽  
Vol 13 (7S_Part_26) ◽  
pp. P1278-P1278 ◽  
Author(s):  
Zhizhen Zeng ◽  
Partricia J. Miller ◽  
Brett M. Connolly ◽  
Stacey S. O'Malley ◽  
Talakad Lohith ◽  
...  
Keyword(s):  
Binding Studies ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Subcortical Regions

Mechanistic insights into a novel chromone-appended Cu(ii) anticancer drug entity: in vitro binding profile with DNA/RNA substrates and cytotoxic activity against MCF-7 and HepG2 cancer cells

2015 ◽  
Vol 44 (22) ◽  
pp. 10330-10342 ◽  
Author(s):  
Imtiyaz Yousuf ◽  
Farukh Arjmand ◽  
Sartaj Tabassum ◽  
Loic Toupet ◽  
Rais Ahmad Khan ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Mtt Assay ◽  
Rna Binding ◽  
Ros Generation ◽  
Binding Studies ◽  
Binding Profile ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Mcf 7

DNA/RNA binding studies, the MTT assay and ROS generation by complex 1.

Phosphonium-Containing Resins as Bile Acid Sorbents: In-Vitro Binding Studies

1996 ◽  
Vol 33 (2) ◽  
pp. 221-232 ◽  
Author(s):  
S.-D. Clas ◽  
G. R. Brown ◽  
L. E. St-Pierre
Keyword(s):  
Bile Acid ◽  
Binding Studies ◽  
In Vitro Binding ◽  
Vitro Binding

scholarly journals The Snf1 protein kinase and its activating subunit, Snf4, interact with distinct domains of the Sip1/Sip2/Gal83 component in the kinase complex.

1997 ◽  
Vol 17 (4) ◽  
pp. 2099-2106 ◽  
Author(s):  
R Jiang ◽  
M Carlson
Keyword(s):  
Protein Kinase ◽  
Regulatory Domain ◽  
Glucose Starvation ◽  
Binding Studies ◽  
Triple Mutant ◽  
Yeast Saccharomyces Cerevisiae ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Two Hybrid

The Snf1 protein kinase plays a central role in the response to glucose starvation in the yeast Saccharomyces cerevisiae. Previously, we showed that two-hybrid interaction between Snf1 and its activating subunit, Snf4, is inhibited by high levels of glucose. These findings, together with biochemical evidence that Snf1 and Snf4 remain associated in cells grown in glucose, suggested that another protein (or proteins) anchors Snf1 and Snf4 into a complex. Here, we examine the possibility that a family of proteins, comprising Sip1, Sip2, and Gal83, serves this purpose. We first show that the fraction of cellular Snf4 protein that is complexed with Snf1 is reduced in a sip1delta sip2delta gal83delta triple mutant. We then present evidence that Sip1, Sip2, and Gal83 each interact independently with both Snf1 and Snf4 via distinct domains. A conserved internal region binds to the Snf1 regulatory domain, and the conserved C-terminal ASC domain binds to Snf4. Interactions were mapped by using the two-hybrid system and were confirmed by in vitro binding studies. These findings indicate that the Sip1/Sip2/Gal83 family anchors Snf1 and Snf4 into a complex. Finally, the interaction of the yeast Sip2 protein with a plant Snf1 homolog suggests that this function is conserved in plants.

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