The Experts below are selected from a list of 43935 Experts worldwide ranked by ideXlab platform
Narla Mohandas - One of the best experts on this subject based on the ideXlab platform.
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regulation of protein 4 1r p55 and glycophorin c ternary complex in human Erythrocyte Membrane
Journal of Biological Chemistry, 2000Co-Authors: Wataru Nunomura, Yuichi Takakuwa, Marilyn Parra, John G Conboy, Narla MohandasAbstract:Abstract Three binary protein-protein interactions, glycophorin C (GPC)-4.1R, GPC-p55, and p55–4.1R, constitute the GPC-4.1R-p55 ternary complex in the Erythrocyte Membrane. Little is known regarding the molecular basis for the interaction of 4.1R with either GPC or p55 and regarding the role of 4.1R in regulating the various protein-protein interactions that constitute the GPC-4.1R-p55 ternary complex. In the present study, we present evidence that sequences in the 30-kDa domain encoded by exon 8 and exon 10 of 4.1R constitute the binding interfaces for GPC and p55, respectively. We further show that 4.1R increases the affinity of p55 binding to GPC by an order of magnitude, implying that 4.1R modulates the interaction between p55 and GPC. Finally, we document that binding of calmodulin to 4.1R decreases the affinity of 4.1R interactions with both p55 and GPC in a Ca2+-dependent manner, implying that the GPC-4.1R-p55 ternary protein complex can undergo dynamic regulation in the Erythrocyte Membrane. Taken together, these findings have enabled us to identify an important role for 4.1R in regulating the GPC-4.1R-p55 ternary complex in the Erythrocyte Membrane.
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modulation of Erythrocyte Membrane mechanical function by beta spectrin phosphorylation and dephosphorylation
Journal of Biological Chemistry, 1995Co-Authors: Sumie Manno, Yuichi Takakuwa, Kaoru Nagao, Narla MohandasAbstract:The mechanical properties of human Erythrocyte Membrane are largely regulated by submembranous protein skeleton whose principal components are alpha- and beta-spectrin, actin, protein 4.1, adducin, and dematin. All of these proteins, except for actin, are phosphorylated by various kinases present in the Erythrocyte. In vitro studies with purified skeletal proteins and various kinases has shown that while phosphorylation of these proteins can modify some of the binary and ternary protein interactions, it has no effect on certain other interactions between these proteins. Most importantly, at present there is no direct evidence that phosphorylation of skeletal protein(s) alters the function of the intact Membrane. To explore this critical issue, we have developed experimental strategies to determine the functional consequences of phosphorylation of beta-spectrin on mechanical properties of intact Erythrocyte Membrane. We have been able to document that Membrane mechanical stability is exquisitely regulated by phosphorylation of beta-spectrin by Membrane-bound casein kinase I. Increased phosphorylation of beta-spectrin decreases Membrane mechanical stability while decreased phosphorylation increases Membrane mechanical stability. Our data for the first time demonstrate that phosphorylation of a skeletal protein in situ can modulate physiological function of native Erythrocyte Membrane.
Avik Basu - One of the best experts on this subject based on the ideXlab platform.
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Proteome analysis of the triton-insoluble Erythrocyte Membrane skeleton.
Journal of Proteomics, 2015Co-Authors: Avik Basu, Sandra L. Harper, Esther N. Pesciotta, Kaye D. Speicher, Abhijit Chakrabarti, David W SpeicherAbstract:Abstract Erythrocyte shape and Membrane integrity is imparted by the Membrane skeleton, which can be isolated as a Triton X-100 insoluble structure that retains the biconcave shape of intact Erythrocytes, indicating isolation of essentially intact Membrane skeletons. These Erythrocyte “Triton Skeletons” have been studied morphologically and biochemically, but unbiased proteome analysis of this substructure of the Membrane has not been reported. In this study, different extraction buffers and in-depth proteome analyses were used to more fully define the protein composition of this functionally critical macromolecular complex. As expected, the major, well-characterized Membrane skeleton proteins and their associated Membrane anchors were recovered in good yield. But surprisingly, a substantial number of additional proteins that are not considered in Erythrocyte Membrane skeleton models were recovered in high yields, including myosin-9, lipid raft proteins (stomatin, flotillin1 and 2), multiple chaperone proteins (HSPs, protein disulfide isomerase and calnexin), and several other proteins. These results show that the Membrane skeleton is substantially more complex than previous biochemical studies indicated, and it apparently has localized regions with unique protein compositions and functions. This comprehensive catalog of the Membrane skeleton should lead to new insights into Erythrocyte Membrane biology and pathogenic mutations that perturb Membrane stability. Biological significance Current models of Erythrocyte Membranes describe fairly simple homogenous structures that are incomplete. Proteome analysis of the Erythrocyte Membrane skeleton shows that it is quite complex and includes a substantial number of proteins whose roles and locations in the Membrane are not well defined. Further elucidation of interactions involving these proteins and definition of microdomains in the Membrane that contain these proteins should yield novel insights into how the Membrane skeleton produces the normal biconcave Erythrocyte shape and how it is perturbed in pathological conditions that destabilize the Membrane.
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Defects in Erythrocyte Membrane Skeletal Architecture
Advances in experimental medicine and biology, 2014Co-Authors: Avik Basu, Abhijit ChakrabartiAbstract:The structure and function of Membrane skeleton (MS) is gaining its significance in the recent years. Considerable development has been made in our understanding of the role of the many Erythrocyte MS proteins in regulating normal and pathologic features of Erythrocyte Membrane physiology. This review focuses on Erythrocyte MS, its organization, protein-protein and protein lipid interactions. Various functions of MS and their alterations are also dealt here. The molecular defects that result in the most common Erythrocyte Membrane disorder, hereditary spherocytosis and the diverse defect that produce hereditary elliptocytosis are briefly described here. The most common molecular lesions in these Erythrocyte phenotypes involve mutations in α and β-spectrin genes; ankyrin, band 3, 4.1R, 4.2 and Glycophorin C can also produce such hereditary hemolytic disorders. Finally, we have explored MS alterations induced by the malarial parasite, Plasmodium falciparum, in the infected Erythrocytes. This review article attests to the enormous progress in our understanding of the contribution of Erythrocyte Membrane skeletal proteins to human diseases.
Abhijit Chakrabarti - One of the best experts on this subject based on the ideXlab platform.
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Proteome analysis of the triton-insoluble Erythrocyte Membrane skeleton.
Journal of Proteomics, 2015Co-Authors: Avik Basu, Sandra L. Harper, Esther N. Pesciotta, Kaye D. Speicher, Abhijit Chakrabarti, David W SpeicherAbstract:Abstract Erythrocyte shape and Membrane integrity is imparted by the Membrane skeleton, which can be isolated as a Triton X-100 insoluble structure that retains the biconcave shape of intact Erythrocytes, indicating isolation of essentially intact Membrane skeletons. These Erythrocyte “Triton Skeletons” have been studied morphologically and biochemically, but unbiased proteome analysis of this substructure of the Membrane has not been reported. In this study, different extraction buffers and in-depth proteome analyses were used to more fully define the protein composition of this functionally critical macromolecular complex. As expected, the major, well-characterized Membrane skeleton proteins and their associated Membrane anchors were recovered in good yield. But surprisingly, a substantial number of additional proteins that are not considered in Erythrocyte Membrane skeleton models were recovered in high yields, including myosin-9, lipid raft proteins (stomatin, flotillin1 and 2), multiple chaperone proteins (HSPs, protein disulfide isomerase and calnexin), and several other proteins. These results show that the Membrane skeleton is substantially more complex than previous biochemical studies indicated, and it apparently has localized regions with unique protein compositions and functions. This comprehensive catalog of the Membrane skeleton should lead to new insights into Erythrocyte Membrane biology and pathogenic mutations that perturb Membrane stability. Biological significance Current models of Erythrocyte Membranes describe fairly simple homogenous structures that are incomplete. Proteome analysis of the Erythrocyte Membrane skeleton shows that it is quite complex and includes a substantial number of proteins whose roles and locations in the Membrane are not well defined. Further elucidation of interactions involving these proteins and definition of microdomains in the Membrane that contain these proteins should yield novel insights into how the Membrane skeleton produces the normal biconcave Erythrocyte shape and how it is perturbed in pathological conditions that destabilize the Membrane.
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Defects in Erythrocyte Membrane Skeletal Architecture
Advances in experimental medicine and biology, 2014Co-Authors: Avik Basu, Abhijit ChakrabartiAbstract:The structure and function of Membrane skeleton (MS) is gaining its significance in the recent years. Considerable development has been made in our understanding of the role of the many Erythrocyte MS proteins in regulating normal and pathologic features of Erythrocyte Membrane physiology. This review focuses on Erythrocyte MS, its organization, protein-protein and protein lipid interactions. Various functions of MS and their alterations are also dealt here. The molecular defects that result in the most common Erythrocyte Membrane disorder, hereditary spherocytosis and the diverse defect that produce hereditary elliptocytosis are briefly described here. The most common molecular lesions in these Erythrocyte phenotypes involve mutations in α and β-spectrin genes; ankyrin, band 3, 4.1R, 4.2 and Glycophorin C can also produce such hereditary hemolytic disorders. Finally, we have explored MS alterations induced by the malarial parasite, Plasmodium falciparum, in the infected Erythrocytes. This review article attests to the enormous progress in our understanding of the contribution of Erythrocyte Membrane skeletal proteins to human diseases.
David W Speicher - One of the best experts on this subject based on the ideXlab platform.
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Proteome analysis of the triton-insoluble Erythrocyte Membrane skeleton.
Journal of Proteomics, 2015Co-Authors: Avik Basu, Sandra L. Harper, Esther N. Pesciotta, Kaye D. Speicher, Abhijit Chakrabarti, David W SpeicherAbstract:Abstract Erythrocyte shape and Membrane integrity is imparted by the Membrane skeleton, which can be isolated as a Triton X-100 insoluble structure that retains the biconcave shape of intact Erythrocytes, indicating isolation of essentially intact Membrane skeletons. These Erythrocyte “Triton Skeletons” have been studied morphologically and biochemically, but unbiased proteome analysis of this substructure of the Membrane has not been reported. In this study, different extraction buffers and in-depth proteome analyses were used to more fully define the protein composition of this functionally critical macromolecular complex. As expected, the major, well-characterized Membrane skeleton proteins and their associated Membrane anchors were recovered in good yield. But surprisingly, a substantial number of additional proteins that are not considered in Erythrocyte Membrane skeleton models were recovered in high yields, including myosin-9, lipid raft proteins (stomatin, flotillin1 and 2), multiple chaperone proteins (HSPs, protein disulfide isomerase and calnexin), and several other proteins. These results show that the Membrane skeleton is substantially more complex than previous biochemical studies indicated, and it apparently has localized regions with unique protein compositions and functions. This comprehensive catalog of the Membrane skeleton should lead to new insights into Erythrocyte Membrane biology and pathogenic mutations that perturb Membrane stability. Biological significance Current models of Erythrocyte Membranes describe fairly simple homogenous structures that are incomplete. Proteome analysis of the Erythrocyte Membrane skeleton shows that it is quite complex and includes a substantial number of proteins whose roles and locations in the Membrane are not well defined. Further elucidation of interactions involving these proteins and definition of microdomains in the Membrane that contain these proteins should yield novel insights into how the Membrane skeleton produces the normal biconcave Erythrocyte shape and how it is perturbed in pathological conditions that destabilize the Membrane.
Yuichi Takakuwa - One of the best experts on this subject based on the ideXlab platform.
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regulation of protein 4 1r p55 and glycophorin c ternary complex in human Erythrocyte Membrane
Journal of Biological Chemistry, 2000Co-Authors: Wataru Nunomura, Yuichi Takakuwa, Marilyn Parra, John G Conboy, Narla MohandasAbstract:Abstract Three binary protein-protein interactions, glycophorin C (GPC)-4.1R, GPC-p55, and p55–4.1R, constitute the GPC-4.1R-p55 ternary complex in the Erythrocyte Membrane. Little is known regarding the molecular basis for the interaction of 4.1R with either GPC or p55 and regarding the role of 4.1R in regulating the various protein-protein interactions that constitute the GPC-4.1R-p55 ternary complex. In the present study, we present evidence that sequences in the 30-kDa domain encoded by exon 8 and exon 10 of 4.1R constitute the binding interfaces for GPC and p55, respectively. We further show that 4.1R increases the affinity of p55 binding to GPC by an order of magnitude, implying that 4.1R modulates the interaction between p55 and GPC. Finally, we document that binding of calmodulin to 4.1R decreases the affinity of 4.1R interactions with both p55 and GPC in a Ca2+-dependent manner, implying that the GPC-4.1R-p55 ternary protein complex can undergo dynamic regulation in the Erythrocyte Membrane. Taken together, these findings have enabled us to identify an important role for 4.1R in regulating the GPC-4.1R-p55 ternary complex in the Erythrocyte Membrane.
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modulation of Erythrocyte Membrane mechanical function by beta spectrin phosphorylation and dephosphorylation
Journal of Biological Chemistry, 1995Co-Authors: Sumie Manno, Yuichi Takakuwa, Kaoru Nagao, Narla MohandasAbstract:The mechanical properties of human Erythrocyte Membrane are largely regulated by submembranous protein skeleton whose principal components are alpha- and beta-spectrin, actin, protein 4.1, adducin, and dematin. All of these proteins, except for actin, are phosphorylated by various kinases present in the Erythrocyte. In vitro studies with purified skeletal proteins and various kinases has shown that while phosphorylation of these proteins can modify some of the binary and ternary protein interactions, it has no effect on certain other interactions between these proteins. Most importantly, at present there is no direct evidence that phosphorylation of skeletal protein(s) alters the function of the intact Membrane. To explore this critical issue, we have developed experimental strategies to determine the functional consequences of phosphorylation of beta-spectrin on mechanical properties of intact Erythrocyte Membrane. We have been able to document that Membrane mechanical stability is exquisitely regulated by phosphorylation of beta-spectrin by Membrane-bound casein kinase I. Increased phosphorylation of beta-spectrin decreases Membrane mechanical stability while decreased phosphorylation increases Membrane mechanical stability. Our data for the first time demonstrate that phosphorylation of a skeletal protein in situ can modulate physiological function of native Erythrocyte Membrane.