In Vivo and in Vitro Binding of Microcystin to Protein Phosphatase 1 and 2A

1995 ◽  
Vol 216 (1) ◽  
pp. 162-169 ◽  
Author(s):  
M. Runnegar ◽  
N. Berndt ◽  
S.M. Kong ◽  
E.Y.C. Lee ◽  
L.F. Zhang
Keyword(s):  
Protein Phosphatase ◽  
Protein Phosphatase 1 ◽  
In Vitro Binding ◽  
Vitro Binding

scholarly journals ADP-ribosylation of integrin α7 modulates the binding of integrin α7β1 to laminin

2004 ◽  
Vol 385 (1) ◽  
pp. 309-317 ◽  
Author(s):  
Zhefeng ZHAO ◽  
Joanna GRUSZCZYNSKA-BIEGALA ◽  
Anna ZOLKIEWSKA
Keyword(s):  
C2c12 Myotubes ◽  
Post Translational Modification ◽  
Integrin Β1 ◽  
Adp Ribosylation ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
C2c12 Skeletal Muscle Cells ◽  
Adp Ribosyltransferase

The extracellular domain of integrin α7 is ADP-ribosylated by an arginine-specific ecto-ADP-ribosyltransferase after adding exogenous NAD+ to intact C2C12 skeletal muscle cells. The effect of ADP-ribosylation on the structure or function of integrin α7β1 has not been explored. In the present study, we show that ADP-ribosylation of integrin α7 takes place exclusively in differentiated myotubes and that this post-translational modification modulates the affinity of α7β1 dimer for its ligand, laminin. ADP-ribosylation in the 37-kDa ‘stalk’ region of α7 that takes place at micromolar NAD+ concentrations increases the binding of the α7β1 dimer to laminin. Increased in vitro binding of integrin α7β1 to laminin after ADP-ribosylation of the 37-kDa fragment of α7 requires the presence of Mn2+ and it is not observed in the presence of Mg2+. In contrast, ADP-ribosylation of the 63-kDa N-terminal region comprising the ligand-binding site of α7 that occurs at approx. 100 μM NAD+ inhibits the binding of integrin α7β1 to laminin. Furthermore, incubation of C2C12 myotubes with NAD+ increases the expression of an epitope on integrin β1 subunit recognized by monoclonal antibody 9EG7. We discuss our results based on the current models of integrin activation. We also hypothesize that ADP-ribosylation may represent a mechanism of regulation of integrin α7β1 function in myofibres in vivo when the continuity of the membrane is compromised and NAD+ is available as a substrate for ecto-ADP-ribosylation.

In vitro binding and in vivo biodistribution studies of the neuroprotective peptide humanin using [125I]humanin derivatives

Peptides ◽  
2009 ◽  
Vol 30 (12) ◽  
pp. 2409-2417 ◽  
Author(s):  
Alexandra Evangelou ◽  
Christos Zikos ◽  
Dimitra Benaki ◽  
Maria Pelecanou ◽  
Penelope Bouziotis ◽  
...  
Keyword(s):  
In Vitro Binding ◽  
In Vivo Biodistribution ◽  
Biodistribution Studies ◽  
Vitro Binding

The microtubule- and PP1-binding activities of Drosophila melanogaster Spc105 control the kinetics of SAC satisfaction.

2021 ◽  
Author(s):  
Margaux R. Audett ◽  
Erin L. Johnson ◽  
Jessica M. McGory ◽  
Dylan M. Barcelos ◽  
Evelin Oroszne Szalai ◽  
...  
Keyword(s):  
Protein Binding ◽  
Protein Phosphatase ◽  
Spindle Assembly Checkpoint ◽  
Protein Phosphatase 1 ◽  
Intrinsically Disordered ◽  
Regulatory Circuit ◽  
Cell Assays ◽  
Kinetics Of

KNL1 is a large intrinsically disordered kinetochore (KT) protein that recruits spindle assembly checkpoint (SAC) components to mediate SAC signaling. The N-terminal region (NTR) of KNL1 possesses two activities that have been implicated in SAC silencing: microtubule (MT) binding and protein phosphatase 1 (PP1) recruitment. The NTR of D. melanogaster KNL1 (Spc105) has never been shown to bind MTs nor to recruit PP1. Furthermore, the phospho-regulatory mechanisms known to control SAC protein binding to KNL1 orthologues is absent in D. melanogaster. Here, these apparent discrepancies are resolved using in vitro and cell based-assays. A phospho-regulatory circuit, which utilizes Aurora B kinase (ABK), promotes SAC protein binding to the central disordered region of Spc105 while the NTR binds directly to MTs in vitro and recruits PP1-87B to KTs in vivo. Live-cell assays employing an optogenetic oligomerization tag, and deletion/chimera mutants are used to define the interplay of MT- and PP1-binding by Spc105 and the relative contributions of both activities to the kinetics of SAC satisfaction. [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text]

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 and in vivo clearance of human α2-macroglobulin after reaction with endoproteases from four different classes

1983 ◽  
Vol 114 (2) ◽  
pp. 757-762 ◽  
Author(s):  
Steven R. Feldman ◽  
Kathryn A. Ney ◽  
Steven L. Gonias ◽  
Salvatore V. Pizzo
Keyword(s):  
In Vitro Binding ◽  
Α2 Macroglobulin ◽  
Vitro Binding

scholarly journals Protein-DNA Binding and CpG Methylation at Nucleotide Resolution of Latency-Associated Promoters Qp, Cp, and LMP1p of Epstein-Barr Virus

2001 ◽  
Vol 75 (6) ◽  
pp. 2584-2596 ◽  
Author(s):  
Daniel Salamon ◽  
Maria Takacs ◽  
Dorina Ujvari ◽  
Jörg Uhlig ◽  
Hans Wolf ◽  
...  
Keyword(s):  
Protein Binding ◽  
Promoter Activity ◽  
Cpg Methylation ◽  
Barr Virus ◽  
In Vitro Binding ◽  
Binding Data ◽  
Vitro Binding ◽  
Epstein Barr

ABSTRACT Epstein-Barr viral (EBV) latency-associated promoters Qp, Cp, and LMP1p are crucial for the regulated expression of the EBNA and LMP transcripts in dependence of the latency type. By transient transfection and in vitro binding analyses, many promoter elements and transcription factors have previously been shown to be involved in the activities of these promoters. However, the latency promoters have only partially been examined at the nucleotide level in vivo. Therefore, we undertook a comprehensive analysis of in vivo protein binding and CpG methylation patterns at these promoters in five representative cell lines and correlated the results with the known in vitro binding data and activities of these promoters from previous transfection experiments. Promoter activity inversely correlated with the methylation state of promoters, although Qp was a remarkable exception. Novel protein binding data were obtained for all promoters. For Cp, binding correlated well with promoter activity; for LMP1p and Qp, binding patterns looked similar regardless of promoter activity.

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