Calmodulin region

A significant functional and structural feature of the plasma membrane Ca pumps is the presence of the calmodulin-binding subdomains A and B near the C-terminus (Fig. 3), that imparts calmodulin sensitivity on the Ca transport and ATP hydrolysis [3]. Adjacent to the calmodulin-binding region are two acidic segments (AC) and the P(S) region containing a serine residue that is susceptible to phosphorylation by cAMP-dependent protein kinase [34]. A unique feature of the plasma membrane Ca pump is its activation by acidic phospholipids that are presumed to... 

Suemaru, J., Akiyama, K., Tanabe, Y., Kuroda, S. Methamphetamine decreases calcium-calmodulin dependent protein kinase II activity in discrete rat brain regions. Synapse. 36 155, 2000. 

As mentioned above, the junctional SR is connected to sheets of perpendicular SR (Fig. 4), which extend from the PM through a peripheral cytoplasmic region with lower myofilament density into the myoplasm. It is proposed that during the active state of wave-like [Ca2+]j oscillations, Ca2+ taken up by the junctional SR is released by these perpendicular sheets near the calmodulin, which is tethered to the myosin light chain kinase (MLCK) of the thin filaments (M. Walsh, personal communication, 2001). This process would enhance the specificity and efficiency of Ca2+ regulation of contraction. 

El Far, O., Bofill-Cardona, E Airas, J. M O Connor, V., Boehm, S., Freissmuth, M et al. (2001) Mapping of calmodulin and Gpy binding domains within the C-terminal region of the metabotropic glutamate receptor 7A. J. Biol. Chem. 276, 30662-30669. 

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