Association between plasma membrane (Ca+Mg) ATPase and calpain/calpastatin system in rat erythrocytes.
We studied the activity of plasma membrane (Ca+Mg)ATPase from erythrocytes of Milan hypertensive rat strain (MHS) and Milan low calpastatin rat strain (MLCS), that show an activity level of the specific calpain inhibitor, calpastatin, about five fold reduced in comparison with the Milan normotensive rat strain (MNS), while the protease activity level is similar. This imbalance of calpain:calpastatin ratio leads to a decrease of the erythrocyte plasma membrane (Ca+Mg)ATPase activity and to the appearance of 124 kDa fragments, which are the typical products of proteolytic calpain action on the 136 kDa (Ca+Mg)ATPase native form.
Soldati
L
L
Department of Sciences and Biochemical Technologies, University of Milano, Italy.
Vezzoli
G
G
Salardi
S
S
Spaventa
R
R
Barber
B R
BR
Azzani
T
T
Bianchi
G
G
D000818:Animals; D001794:Blood Pressure; D015153:Blotting, Western; D017301:Ca(2+) Mg(2+)-ATPase / Q000097:blood* / Q000302:isolation & purification; D002135:Calcium-Binding Proteins / Q000097:blood* / Q000302:isolation & purification; D002154:Calpain / Q000037:antagonists & inhibitors / Q000097:blood* / Q000302:isolation & purification; D004791:Enzyme Inhibitors / Q000097:blood; D004910:Erythrocyte Membrane / Q000201:enzymology / Q000378:metabolism*; D006973:Hypertension / Q000097:blood* / Q000235:genetics / Q000503:physiopathology; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011922:Rats, Mutant Strains
D002135:Calcium-Binding Proteins; D004791:Enzyme Inhibitors; C033668:calpastatin; D002154:Calpain; D017301:Ca(2+) Mg(2+)-ATPase