%0 Journal Article %1 Li_1993_11489 %A Li, Z. P. %A Burke, E. P. %A Frank, J. S. %A Bennett, V. %A Philipson, K. D. %D 1993 %J J. Biol. Chem. %K /&/ Animals; Ankyrins, Antibody Binding; Carrier Cell Chloride Dogs; Erythrocytes, Fluorescent Kinetics; Line; Moths; Myocardium, Protein Proteins, Rabbits; Sarcolemma, Sodium Symporters; Technique; Transfection analysis/metabolism; isolation metabolism; purification/metabolism; %N 16 %P 11489--11491 %T The cardiac Na$^+$-Ca$^2+$ exchanger binds to the cytoskeletal protein ankyrin. %V 268 %X Na$^+$-Ca$^2+$ exchange is the major pathway of Ca$^2+$ efflux during excitation-contraction coupling in cardiac muscle. The Na$^+$-Ca$^2+$ exchanger is present in cardiac transverse tubules with an apparent high density (Frank, J.S., Mottino, G., Reid, D., Molday, R. S., and Philipson, K.D. (1992) J. Cell Biol. 117, 337-345). The mechanism for this localization is unknown but may involve interactions with the cytoskeleton. In the present study, we examined the interaction of the Na$^+$-Ca$^2+$ exchanger with the cytoskeletal protein ankyrin. On immunoblots of isolated canine cardiac sarcolemma, an antibody raised against purified rabbit red blood cell-ankyrin (RBC-ankyrin) recognized a 220-kDa protein, which is the same size as RBC-ankyrin. Alkaline extraction of sarcolemma removed this protein. The Na$^+$-Ca$^2+$ exchange protein, purified from recombinant baculovirus-infected insect cells, bound 125I-labeled-RBC-ankyrin with a KD of 42 +/- 3 nm. 125I-RBC-ankyrin was co-precipitated by antibodies to the Na$^+$-Ca$^2+$ exchanger after preincubation with solubilized cardiac sarcolemma. Myocardial ankyrin could be localized to both surface and T-tubular sarcolemma by immunofluorescence techniques. These results demonstrate that the cardiac Na$^+$-Ca$^2+$ exchanger binds ankyrin with high affinity. This interaction may be important for localizing the Na$^+$-Ca$^2+$ exchanger to specific domains of the sarcolemma.

@article{Li_1993_11489, abstract = {{N}a$^{+}$-{C}a$^{2+}$ exchange is the major pathway of {C}a$^{2+}$ efflux during excitation-contraction coupling in cardiac muscle. The {N}a$^{+}$-{C}a$^{2+}$ exchanger is present in cardiac transverse tubules with an apparent high density (Frank, J.S., Mottino, G., Reid, D., Molday, R. S., and Philipson, K.D. (1992) J. Cell Biol. 117, 337-345). The mechanism for this localization is unknown but may involve interactions with the cytoskeleton. In the present study, we examined the interaction of the {N}a$^{+}$-{C}a$^{2+}$ exchanger with the cytoskeletal protein ankyrin. On immunoblots of isolated canine cardiac sarcolemma, an antibody raised against purified rabbit red blood cell-ankyrin (RBC-ankyrin) recognized a 220-kDa protein, which is the same size as RBC-ankyrin. Alkaline extraction of sarcolemma removed this protein. The {N}a$^{+}$-{C}a$^{2+}$ exchange protein, purified from recombinant baculovirus-infected insect cells, bound 125I-labeled-RBC-ankyrin with a KD of 42 +/- 3 nm. 125I-RBC-ankyrin was co-precipitated by antibodies to the {N}a$^{+}$-{C}a$^{2+}$ exchanger after preincubation with solubilized cardiac sarcolemma. Myocardial ankyrin could be localized to both surface and T-tubular sarcolemma by immunofluorescence techniques. These results demonstrate that the cardiac {N}a$^{+}$-{C}a$^{2+}$ exchanger binds ankyrin with high affinity. This interaction may be important for localizing the {N}a$^{+}$-{C}a$^{2+}$ exchanger to specific domains of the sarcolemma.}, added-at = {2009-06-03T11:20:58.000+0200}, author = {Li, Z. P. and Burke, E. P. and Frank, J. S. and Bennett, V. and Philipson, K. D.}, biburl = {https://www.bibsonomy.org/bibtex/284888d915b686a0f8f76e121bdcade15/hake}, description = {The whole bibliography file I use.}, file = {Li_1993_11489.pdf:Li_1993_11489.pdf:PDF}, institution = {Department of Medicine, UCLA School of Medicine 90024-1760.}, interhash = {d7c524534bf5289c02c30ef137aca696}, intrahash = {84888d915b686a0f8f76e121bdcade15}, journal = {J. Biol. Chem.}, keywords = {/&/ Animals; Ankyrins, Antibody Binding; Carrier Cell Chloride Dogs; Erythrocytes, Fluorescent Kinetics; Line; Moths; Myocardium, Protein Proteins, Rabbits; Sarcolemma, Sodium Symporters; Technique; Transfection analysis/metabolism; isolation metabolism; purification/metabolism;}, month = Jun, number = 16, pages = {11489--11491}, pdf = {Li_1993_11489.pdf}, pmid = {8505285}, timestamp = {2009-06-03T11:21:20.000+0200}, title = {The cardiac {N}a$^{+}$-{C}a$^{2+}$ exchanger binds to the cytoskeletal protein ankyrin.}, volume = 268, year = 1993 }