The microsomal fraction of chicken cerebellum expresses a large amount of Ca(2+)-ATPase (105 kDa), which is phosphorylated by ATP in the presence of Ca2+. The Ca(2+)-ATPase activity is highly sensitive to temperature and to the presence of detergents. This ATPase has kinetic properties similar to those of chicken skeletal-muscle sarcoplasmic reticulum, as (i) it is activated by low (microM) and inhibited by high (mM) Ca2+ concentrations, (ii) it shows biphasic activation with ATP and (iii) it is inhibited by vanadate. However, the vanadate-sensitivity is at least 10 times greater than that observed in chicken skeletal or cardiac sarcoplasmic-reticulum Ca(2+)-ATPases. Thus, despite cross-reacting with antibodies against the cardiac and skeletal isoforms, the cerebellar microsomal Ca(2+)-ATPase appears to be distinct from both muscle enzymes. The Ca(2+)-ATPase is concentrated in, but not exclusive to, Purkinje neurons. In Purkinje neurons the Ca(2+)-ATPase appears to be expressed throughout the cell body, the dendritic tree (and the spines) and the axons. At the electron-microscope level the Ca(2+)-ATPase is found in smooth and rough endoplasmic-reticulum cisternae as well as in other, yet unidentified, smooth-surfaced structures.

Michelangeli, F., Di Virgilio, F., Villa, A., Podini, P., Meldolesi, J., Pozzan, T. (1991). Identification, kinetic properties and intracellular localization of the (Ca(2+)-Mg2+)-ATPase from the intracellular stores of chicken cerebellum. BIOCHEMICAL JOURNAL, 275(3), 555-561 [10.1042/bj2750555].

Identification, kinetic properties and intracellular localization of the (Ca(2+)-Mg2+)-ATPase from the intracellular stores of chicken cerebellum

VILLA, ANTONELLO;
1991

Abstract

The microsomal fraction of chicken cerebellum expresses a large amount of Ca(2+)-ATPase (105 kDa), which is phosphorylated by ATP in the presence of Ca2+. The Ca(2+)-ATPase activity is highly sensitive to temperature and to the presence of detergents. This ATPase has kinetic properties similar to those of chicken skeletal-muscle sarcoplasmic reticulum, as (i) it is activated by low (microM) and inhibited by high (mM) Ca2+ concentrations, (ii) it shows biphasic activation with ATP and (iii) it is inhibited by vanadate. However, the vanadate-sensitivity is at least 10 times greater than that observed in chicken skeletal or cardiac sarcoplasmic-reticulum Ca(2+)-ATPases. Thus, despite cross-reacting with antibodies against the cardiac and skeletal isoforms, the cerebellar microsomal Ca(2+)-ATPase appears to be distinct from both muscle enzymes. The Ca(2+)-ATPase is concentrated in, but not exclusive to, Purkinje neurons. In Purkinje neurons the Ca(2+)-ATPase appears to be expressed throughout the cell body, the dendritic tree (and the spines) and the axons. At the electron-microscope level the Ca(2+)-ATPase is found in smooth and rough endoplasmic-reticulum cisternae as well as in other, yet unidentified, smooth-surfaced structures.
Articolo in rivista - Articolo scientifico
Axons; Calcium-Transporting ATPases; Endoplasmic Reticulum; Adenosine Triphosphate; Animals; Calcium; Vanadates; Kinetics; Enzyme Activation; Cerebellum; Purkinje Cells; Microscopy, Electron; Sarcoplasmic Reticulum; Microsomes; Muscles; Chickens
English
1-mag-1991
275
3
555
561
none
Michelangeli, F., Di Virgilio, F., Villa, A., Podini, P., Meldolesi, J., Pozzan, T. (1991). Identification, kinetic properties and intracellular localization of the (Ca(2+)-Mg2+)-ATPase from the intracellular stores of chicken cerebellum. BIOCHEMICAL JOURNAL, 275(3), 555-561 [10.1042/bj2750555].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/18437
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