scholarly journals Erratum

1991 ◽  
Vol 11 (4) ◽  
pp. 706-706
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Equilibrium State ◽  
Rat Brain ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Adp Ribosylation ◽  
Gtp Binding ◽  
Reconstituted System ◽  
Α Subunits

Ischemia of Rat Brain Decreases Pertussis Toxin-Catalyzed [32P] ADP Ribosylation of GTP-Binding Proteins (Gi1 and G0) in Membranes Katsunobu Takenaka, Yasunori Kanaho, Koh-ichi Nagata, Noboru Sakai, Hiromu Yamada, Yoshinori Nozawa [ Originally published in Journal of Cerebral Blood Flow and Metabolism 1991;11:155–160] On page 158 of the above, arrows were erroneously deleted from the equation in the following passage: Heterotrimers of G proteins that bind GDP to α subunits seem to be the preferred substrates for PTcatalyzed ADP ribosylation since guanine nucleotides (GDP and GTP) and 13'Y subunits stimulate ADP ribosylation in the reconstituted system and in membranes (Tsai et aI., 1984). These results indicate that the G proteins may exist at the equilibrium state as shown below: This omission was the result of a typesetting error, which the publisher regrets.

Ischemia of Rat Brain Decreases Pertussis Toxin-Catalyzed [32P]ADP Ribosylation of GTP-Binding Proteins (Gi1 and G0) in Membranes

1991 ◽  
Vol 11 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Katsunobu Takenaka ◽  
Yasunori Kanaho ◽  
Koh-Ichi Nagata ◽  
Noboru Sakai ◽  
Hiromu Yamada ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Molecular Basis ◽  
Guanine Nucleotides ◽  
Qualitative And Quantitative ◽  
Adp Ribosylation ◽  
Quantitative Changes ◽  
Control Stimulation ◽  
Stimulation Of

As an approach to understanding the molecular basis of the pathophysiology of cerebral ischemia, we examined qualitative and quantitative changes in pertussis toxin substrates, Gi1 and G0, in the membrane of rat cerebral cortex after decapitation. Within 1 min after decapitation, the extent of pertussis toxin-catalyzed [32P]ADP ribosylation of the G proteins in the cerebral cortex membrane was significantly decreased and the magnitude of the decrease became slightly larger upon further incubation of the decapitated brain. Addition of guanine nucleotides, GTP and GDP, or the purified βγ subunits of transducin to the membranes of control and ischemic cerebral cortex stimulated [32P]ADP ribosylation of the G proteins. The stimulation of [32P]ADP ribosylation in the control situation by guanine nucleotides was almost to the same extent as that in ischemia. However, the stimulation by transducin βγ subunits was different; the control stimulation was greater than that in ischemia. In immunoblots probed with antibodies against Gi1α G0α and Tβ, the immunoreactivity of the corresponding proteins in ischemia was similar to that in control, suggesting that the amounts of G proteins were not changed in ischemia. These results suggest that ischemia accelerates the dissociation of α–GDP–βγ to α–GDP and free βγ and causes the denaturation of the dissociated α–GDP, thereby decreasing [32P]ADP ribosylation.

Effects of lithium ion on ADP ribosylation of inhibitory GTP-binding protein by pertussis toxin, islet-activating protein

1991 ◽  
Vol 206 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Hideo Kawamoto ◽  
Yasuhiro Watanabe ◽  
Taro Imaizumi ◽  
Tadaaki Iwasaki ◽  
Hiroshi Yoshida
Keyword(s):  
Pertussis Toxin ◽  
Binding Protein ◽  
Lithium Ion ◽  
Gtp Binding Protein ◽  
Adp Ribosylation ◽  
Gtp Binding

scholarly journals Failure of [32P]ADP-ribosylation by pertussis toxin to determine Giα content in membranes from various human tissues. Improved radioimmunological quantification using the 125I-labelled C-terminal decapeptide of retinal transducin

1991 ◽  
Vol 277 (1) ◽  
pp. 223-229 ◽  
Author(s):  
M Böhm ◽  
K Larisch ◽  
E Erdmann ◽  
M Camps ◽  
K Jakobs ◽  
...  
Keyword(s):  
G Proteins ◽  
Pertussis Toxin ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Polyclonal Antiserum ◽  
Covalent Modification ◽  
Striking Difference ◽  
Left Ventricular Myocardium ◽  
Western Blots ◽  
Adp Ribosylation

The quantitative determination of pertussis-toxin-sensitive guanine-nucleotide-binding proteins (G-proteins) in cell membranes is still a problem. Pertussis-toxin-catalysed [32P]ADP-ribosylation strongly relies on the substrate quality of the alpha-subunits and is influenced by the concentration of nucleotides, beta gamma-subunits, the physicochemical properties of the membranes influencing the availability of Gi alpha for pertussis toxin, and covalent modification of Gi alpha. Quantification of immunoreactive material on Western blots can be only imprecisely performed by two-dimensional densitometry. In order to generate a method for quantification of pertussis-toxin-sensitive G-proteins in membranes we have developed a fast and sensitive radioimmunoassay. The C-terminal decapeptide of retinal transducin alpha (KENLKDCGLF) was 125I-labelled and used as tracer. Polyclonal antiserum (DS 4) was raised against this peptide. Gi alpha proteins were determined by competition of solubilized membranes for 125I-KENLKDCGLF binding to DS 4 using dilutions of retinal transducin alpha as standard. The interassay variation was less than 10%, with a sensitivity of 2.5 micrograms/ml. The density of Gi alpha was highest in human adipose tissue, followed by HL60 cells, lung, mononuclear leucocytes, thrombocytes and left ventricular myocardium. A striking difference was observed between the density of Gi alpha and the amount of incorporation of [32P]ADP-ribose into the 40 kDa membrane proteins by pertussis toxin in the same samples. This is also demonstrated by comparison of the weak [32P]ATP-ribosylation of pertussis toxin substrates with the density of immunoreactive Gi alpha on Western blots in tissues such as lung. This study shows that the Gi alpha content can be exactly determined by a sensitive and fast radioimmunoassay using iodinated synthetic peptide homologues of Gi alpha proteins. Radioimmunological quantification of Gi alpha might be able to detect the ‘true’ Gi alpha content of membranes without being hampered by influences on the [32P]ADP-ribosylation reaction. It is concluded that this newly developed method may become an important tool for studying expression of Gi alpha proteins in a variety of tissues or cell types, and for precisely quantifying the changes caused by pathological conditions.

Diffuse optical tomography of hemoglobin concentrations, and cerebral blood flow in rat brain during focal ischemia.

2002 ◽  
Author(s):  
Joseph P. Culver ◽  
Daisuke Furuya ◽  
Joel H. Greenberg ◽  
Turgut Durduran ◽  
Cecil Cheung ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Rat Brain ◽  
Optical Tomography ◽  
Diffuse Optical Tomography ◽  
Focal Ischemia
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