Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii
cAMP sites of the cAMP‐dependent protein kinase from the fungus Mucor rouxii have been characterized through the study of the effects of cAMP and of cAMP analogs on the phosphotransferase activity and through binding kinetics. The tetrameric holoenzyme, which contains two regulatory (R) and two cata...
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1989
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00142956_v179_n2_p429_Paveto http://hdl.handle.net/20.500.12110/paper_00142956_v179_n2_p429_Paveto |
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paper:paper_00142956_v179_n2_p429_Paveto2023-06-08T14:36:40Z Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii Paveto, María Cristina Moreno, Silvia cyclic amp cyclic amp dependent protein kinase cyclic amp derivative radioisotope binding site fungus mucor rouxii nonhuman priority journal Allosteric Regulation Binding Sites Catalysis Centrifugation, Density Gradient Cyclic AMP Enzyme Activation Hydrolysis Isoenzymes Mucor Protein Binding Protein Kinases Support, Non-U.S. Gov't Trypsin cAMP sites of the cAMP‐dependent protein kinase from the fungus Mucor rouxii have been characterized through the study of the effects of cAMP and of cAMP analogs on the phosphotransferase activity and through binding kinetics. The tetrameric holoenzyme, which contains two regulatory (R) and two catalytic (C) subunits, exhibited positive cooperativity in activation by cAMP, suggesting multiple cAMP‐binding sites. Several other results indicated that the Mucor kinase contained two different cooperative cAMP‐binding sites on each R subunit, with properties similar to those of the mammalian cAMP‐dependent protein kinase. Under optimum binding conditions, the [3H]cAMP dissociation behavior indicated equal amounts of two components which had dissociation rate constants of 0.09 min−1 (site 1) and 0.90 min−1 (site 2) at 30°C. Two cAMP‐binding sites could also be distinguished by C‐8 cAMP analogs (site‐1‐selective) and C‐6 cAMP analogs (site‐2‐selective); combinations of site‐1‐ and site‐2‐selective analogs were synergistic in protein kinase activation. The two different cooperative binding sites were probably located on the same R subunit, since the proteolytically derived dimeric form of the enzyme, which contained one R and one C component, retained the salient properties of the untreated tetrameric enzyme. Unlike any of the mammalian cyclic‐nucleotide‐dependent isozymes described thus far, the Mucor kinase was much more potently activated by C‐6 cAMP analogs than by C‐8 cAMP analogs. In the ternary complex formed by the native Mucor tetramer and cAMP, only the two sites 1 contained bound cAMP, a feature which has also not yet been demonstrated for the mammalian cAMP‐dependent protein kinase. Copyright © 1989, Wiley Blackwell. All rights reserved Fil:Paveto, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Moreno, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1989 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00142956_v179_n2_p429_Paveto http://hdl.handle.net/20.500.12110/paper_00142956_v179_n2_p429_Paveto |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
cyclic amp cyclic amp dependent protein kinase cyclic amp derivative radioisotope binding site fungus mucor rouxii nonhuman priority journal Allosteric Regulation Binding Sites Catalysis Centrifugation, Density Gradient Cyclic AMP Enzyme Activation Hydrolysis Isoenzymes Mucor Protein Binding Protein Kinases Support, Non-U.S. Gov't Trypsin |
| spellingShingle |
cyclic amp cyclic amp dependent protein kinase cyclic amp derivative radioisotope binding site fungus mucor rouxii nonhuman priority journal Allosteric Regulation Binding Sites Catalysis Centrifugation, Density Gradient Cyclic AMP Enzyme Activation Hydrolysis Isoenzymes Mucor Protein Binding Protein Kinases Support, Non-U.S. Gov't Trypsin Paveto, María Cristina Moreno, Silvia Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii |
| topic_facet |
cyclic amp cyclic amp dependent protein kinase cyclic amp derivative radioisotope binding site fungus mucor rouxii nonhuman priority journal Allosteric Regulation Binding Sites Catalysis Centrifugation, Density Gradient Cyclic AMP Enzyme Activation Hydrolysis Isoenzymes Mucor Protein Binding Protein Kinases Support, Non-U.S. Gov't Trypsin |
| description |
cAMP sites of the cAMP‐dependent protein kinase from the fungus Mucor rouxii have been characterized through the study of the effects of cAMP and of cAMP analogs on the phosphotransferase activity and through binding kinetics. The tetrameric holoenzyme, which contains two regulatory (R) and two catalytic (C) subunits, exhibited positive cooperativity in activation by cAMP, suggesting multiple cAMP‐binding sites. Several other results indicated that the Mucor kinase contained two different cooperative cAMP‐binding sites on each R subunit, with properties similar to those of the mammalian cAMP‐dependent protein kinase. Under optimum binding conditions, the [3H]cAMP dissociation behavior indicated equal amounts of two components which had dissociation rate constants of 0.09 min−1 (site 1) and 0.90 min−1 (site 2) at 30°C. Two cAMP‐binding sites could also be distinguished by C‐8 cAMP analogs (site‐1‐selective) and C‐6 cAMP analogs (site‐2‐selective); combinations of site‐1‐ and site‐2‐selective analogs were synergistic in protein kinase activation. The two different cooperative binding sites were probably located on the same R subunit, since the proteolytically derived dimeric form of the enzyme, which contained one R and one C component, retained the salient properties of the untreated tetrameric enzyme. Unlike any of the mammalian cyclic‐nucleotide‐dependent isozymes described thus far, the Mucor kinase was much more potently activated by C‐6 cAMP analogs than by C‐8 cAMP analogs. In the ternary complex formed by the native Mucor tetramer and cAMP, only the two sites 1 contained bound cAMP, a feature which has also not yet been demonstrated for the mammalian cAMP‐dependent protein kinase. Copyright © 1989, Wiley Blackwell. All rights reserved |
| author |
Paveto, María Cristina Moreno, Silvia |
| author_facet |
Paveto, María Cristina Moreno, Silvia |
| author_sort |
Paveto, María Cristina |
| title |
Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii |
| title_short |
Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii |
| title_full |
Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii |
| title_fullStr |
Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii |
| title_full_unstemmed |
Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii |
| title_sort |
two different intrachain camp sites in the camp‐dependent protein kinase of the dimorphic fungus mucor rouxii |
| publishDate |
1989 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00142956_v179_n2_p429_Paveto http://hdl.handle.net/20.500.12110/paper_00142956_v179_n2_p429_Paveto |
| work_keys_str_mv |
AT pavetomariacristina twodifferentintrachaincampsitesinthecampdependentproteinkinaseofthedimorphicfungusmucorrouxii AT morenosilvia twodifferentintrachaincampsitesinthecampdependentproteinkinaseofthedimorphicfungusmucorrouxii |
| _version_ |
1768542156120653824 |