G-protein from Medicago sativa: Functional association to photoreceptors
G-protein subunits were characterized from Medicago sativa (alfalfa) seedlings. Crude membranes and GTP-Sepharose-purified fractions were electrophoresed on SDS/polyacrylamide gels and analysed by Western blotting with 9193 (anti-α(common)) and AS/7 (anti-α(t), anti-α(i1) and anti α(i2)) polyclonal...
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1993
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02646021_v291_n2_p383_Muschietti http://hdl.handle.net/20.500.12110/paper_02646021_v291_n2_p383_Muschietti |
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paper:paper_02646021_v291_n2_p383_Muschietti2023-06-08T15:23:08Z G-protein from Medicago sativa: Functional association to photoreceptors cholera toxin guanine nucleotide binding protein guanosine 5' o (3 thiotriphosphate) pertussis toxin polyclonal antibody adenosine diphosphate ribosylation alfalfa article illumination immunoblotting irradiation molecular weight nonhuman photoaffinity labeling photoreceptor plant seed polyacrylamide gel electrophoresis priority journal protein binding protein purification protoplast Medicago sativa G-protein subunits were characterized from Medicago sativa (alfalfa) seedlings. Crude membranes and GTP-Sepharose-purified fractions were electrophoresed on SDS/polyacrylamide gels and analysed by Western blotting with 9193 (anti-α(common)) and AS/7 (anti-α(t), anti-α(i1) and anti α(i2)) polyclonal antibodies. These procedures led to the identification of a specific polypeptide band of about 43 kDa. Another polypeptide reacting with the SW/1 (anti-β) antibody, of about 37 kDa, was also detected. The 43 kDa polypeptide bound specifically [α-32P]GTP by a photoaffinity reaction and was ADP-ribosylated by activated cholera toxin, but not by pertussis toxin. Irradiation of etiolated Medicago sativa protoplast preparations at 660 nm for 1 min produced a maximal increase in the guanosine 5'-[γ-thio]triphosphate (GTP[35S])-binding rate. After this period of irradiation, the binding rate tended to decrease. The effect of a red-light (660 nm) pulse on the binding rate was reversed when it was immediately followed by a period of far-red (> 730 nm) illumination. These results may suggest that activation of GTP[S]binding rate was a consequence of conversion of phytochrome P(r) into the P(f)r form. 1993 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02646021_v291_n2_p383_Muschietti http://hdl.handle.net/20.500.12110/paper_02646021_v291_n2_p383_Muschietti |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
cholera toxin guanine nucleotide binding protein guanosine 5' o (3 thiotriphosphate) pertussis toxin polyclonal antibody adenosine diphosphate ribosylation alfalfa article illumination immunoblotting irradiation molecular weight nonhuman photoaffinity labeling photoreceptor plant seed polyacrylamide gel electrophoresis priority journal protein binding protein purification protoplast Medicago sativa |
spellingShingle |
cholera toxin guanine nucleotide binding protein guanosine 5' o (3 thiotriphosphate) pertussis toxin polyclonal antibody adenosine diphosphate ribosylation alfalfa article illumination immunoblotting irradiation molecular weight nonhuman photoaffinity labeling photoreceptor plant seed polyacrylamide gel electrophoresis priority journal protein binding protein purification protoplast Medicago sativa G-protein from Medicago sativa: Functional association to photoreceptors |
topic_facet |
cholera toxin guanine nucleotide binding protein guanosine 5' o (3 thiotriphosphate) pertussis toxin polyclonal antibody adenosine diphosphate ribosylation alfalfa article illumination immunoblotting irradiation molecular weight nonhuman photoaffinity labeling photoreceptor plant seed polyacrylamide gel electrophoresis priority journal protein binding protein purification protoplast Medicago sativa |
description |
G-protein subunits were characterized from Medicago sativa (alfalfa) seedlings. Crude membranes and GTP-Sepharose-purified fractions were electrophoresed on SDS/polyacrylamide gels and analysed by Western blotting with 9193 (anti-α(common)) and AS/7 (anti-α(t), anti-α(i1) and anti α(i2)) polyclonal antibodies. These procedures led to the identification of a specific polypeptide band of about 43 kDa. Another polypeptide reacting with the SW/1 (anti-β) antibody, of about 37 kDa, was also detected. The 43 kDa polypeptide bound specifically [α-32P]GTP by a photoaffinity reaction and was ADP-ribosylated by activated cholera toxin, but not by pertussis toxin. Irradiation of etiolated Medicago sativa protoplast preparations at 660 nm for 1 min produced a maximal increase in the guanosine 5'-[γ-thio]triphosphate (GTP[35S])-binding rate. After this period of irradiation, the binding rate tended to decrease. The effect of a red-light (660 nm) pulse on the binding rate was reversed when it was immediately followed by a period of far-red (> 730 nm) illumination. These results may suggest that activation of GTP[S]binding rate was a consequence of conversion of phytochrome P(r) into the P(f)r form. |
title |
G-protein from Medicago sativa: Functional association to photoreceptors |
title_short |
G-protein from Medicago sativa: Functional association to photoreceptors |
title_full |
G-protein from Medicago sativa: Functional association to photoreceptors |
title_fullStr |
G-protein from Medicago sativa: Functional association to photoreceptors |
title_full_unstemmed |
G-protein from Medicago sativa: Functional association to photoreceptors |
title_sort |
g-protein from medicago sativa: functional association to photoreceptors |
publishDate |
1993 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02646021_v291_n2_p383_Muschietti http://hdl.handle.net/20.500.12110/paper_02646021_v291_n2_p383_Muschietti |
_version_ |
1768546157661782016 |