FIGURE 5.
Transferring the luminal tail of SLN to PLN. A, topology models of cPLNlong and cPLNshort chimeras (white, cytosolic residues; gray, transmembrane residues; black, luminal residues). Shown are ATPase activity (B) and normalized ATPase activity (C) as a function of calcium concentration for SERCA alone (solid black line), SERCA in the presence of wild-type PLN (solid gray line), and SERCA in the presence of cPLNlong (dashed black line) and cPLNshort (dotted black line). Each data point is the mean ± S.E. (error bars) (n ≥ 4). The Vmax, KCa, and nH are given in Table 1. D, SDS-PAGE of cPLNlong (left lane) and cPLNshort (right lane) chimeras (5 μg per lane; 16% gel). Pentameric and monomeric PLN chimeras are indicated.