Role of FKBP12.6 in cADPR-induced activation of reconstituted ryanodine receptors from arterial smooth muscle. Am J Physiol Heart Circ Physiol 2002 Apr;282(4):H1304-10
Date
03/15/2002Pubmed ID
11893565DOI
10.1152/ajpheart.00843.2001Scopus ID
2-s2.0-0036087476 (requires institutional sign-in at Scopus site) 93 CitationsAbstract
cADP ribose (cADPR) serves as second messenger to activate the ryanodine receptors (RyRs) of the sarcoplasmic reticulum (SR) and mobilize intracellular Ca(2+) in vascular smooth muscle cells. However, the mechanisms mediating the effect of cADPR remain unknown. The present study was designed to determine whether FK-506 binding protein 12.6 (FKBP12.6), an accessory protein of the RyRs, plays a role in cADPR-induced activation of the RyRs. A 12.6-kDa protein was detected in bovine coronary arterial smooth muscle (BCASM) and cultured CASM cells by being immunoblotted with an antibody against FKBP12, which also reacted with FKBP12.6. With the use of planar lipid bilayer clamping techniques, FK-506 (0.01-10 microM) significantly increased the open probability (NP(O)) of reconstituted RyR/Ca(2+) release channels from the SR of CASM. This FK-506-induced activation of RyR/Ca(2+) release channels was abolished by pretreatment with anti-FKBP12 antibody. The RyRs activator cADPR (0.1-10 microM) markedly increased the activity of RyR/Ca(2+) release channels. In the presence of FK-506, cADPR did not further increase the NP(O) of RyR/Ca(2+) release channels. Addition of anti-FKBP12 antibody also completely blocked cADPR-induced activation of these channels, and removal of FKBP12.6 by preincubation with FK-506 and subsequent gradient centrifugation abolished cADPR-induced increase in the NP(O) of RyR/Ca(2+) release channels. We conclude that FKBP12.6 plays a critical role in mediating cADPR-induced activation of RyR/Ca(2+) release channels from the SR of BCASM.
Author List
Tang WX, Chen YF, Zou AP, Campbell WB, Li PLAuthor
William B. Campbell PhD Professor in the Pharmacology and Toxicology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adenosine Diphosphate RiboseAnimals
Antibodies
Blotting, Western
Calcium
Cattle
Coronary Vessels
Cyclic ADP-Ribose
Ion Channel Gating
Lipid Bilayers
Muscle, Smooth, Vascular
Ryanodine Receptor Calcium Release Channel
Tacrolimus
Tacrolimus Binding Protein 1A