High impact information on Jsrp1

• The increases in Ca2+ content were specific to junctional sarcoplasmic reticulum stores, as there were no alterations in the Ca2+ content of the mitochondria or A band [1].
• In the present study, whole skeletal muscle homogenates and sucrose gradient-purified junctional sarcoplasmic reticulum from neonatal wild-type and dyspedic mice were assayed for biochemical and functional markers [2].
• The cytoplasmic domain of JP-45, comprising residues 1-80, interacts with Cav1 [3].
• The junctional SR protein JP-45 affects the functional expression of the voltage-dependent Ca2+ channel Cav1.1 [3].
• JP-45, an integral protein of the junctional face membrane of the skeletal muscle sarcoplasmic reticulum (SR), colocalizes with its Ca2+ -release channel (the ryanodine receptor), and interacts with calsequestrin and the skeletal-muscle dihydropyridine receptor Cav1 [3].

Anatomical context of Jsrp1

• The functional effect of JP-45 on Cav1.1 activity was assessed by investigating charge movement in differentiated C2C12 myotubes after overexpression or depletion of JP-45 [3].
• Quantitative and qualitative analysis of structural changes in the overexpressing as well as in the normally differentiating myocardium illustrate the synthetic pathways and the events in the targeting and delivery of CSQ and JNC to the jSR of the differentiating cardiac myocyte [4].

Associations of Jsrp1 with chemical compounds

• Both these values exceed the limit of resolution of the optical system, but their similarity suggests that at high [EGTA] the Ca(2+) domains in adult mammalian muscle fibers are confined to Ca(2+) release sites located at the junctional sarcoplasmic reticulum (SR) [5].
• Extracellular Na(+) removal lead to Ca(2+) accumulation in the JSR inducing further SR-Ca(2+) release and increased energy release [6].

Analytical, diagnostic and therapeutic context of Jsrp1

• Western blot analysis revealed that isolated triads contained the integral membrane subunits gp91(phox) and p22(phox), which were markedly enriched in isolated transverse tubules but absent from junctional sarcoplasmic reticulum vesicles [7].

References