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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Autores principales: Paveto, C., Passeron, S., Corbin, J.D., Moreno, S.
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spelling todo:paper_00142956_v179_n2_p429_Paveto2023-10-03T14:11:51Z Two different intrachain cAMP sites in the cAMP‐dependent protein kinase of the dimorphic fungus Mucor rouxii Paveto, C. Passeron, S. Corbin, J.D. Moreno, S. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar 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, C.
Passeron, S.
Corbin, J.D.
Moreno, S.
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
format JOUR
author Paveto, C.
Passeron, S.
Corbin, J.D.
Moreno, S.
author_facet Paveto, C.
Passeron, S.
Corbin, J.D.
Moreno, S.
author_sort Paveto, C.
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
url http://hdl.handle.net/20.500.12110/paper_00142956_v179_n2_p429_Paveto
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AT corbinjd twodifferentintrachaincampsitesinthecampdependentproteinkinaseofthedimorphicfungusmucorrouxii
AT morenos twodifferentintrachaincampsitesinthecampdependentproteinkinaseofthedimorphicfungusmucorrouxii
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