Xenbase Image ID: 117681

Figure 6. Site-directed mutagenesis of SERCA2b residue N1036 creates a protein that is no longer responsive to ΔC coexpression, and that resembles SERCA2a. (a) Amino acid sequence comparison between the COOH terminus of SERCA2a and SERCA2b. The eleventh transmembrane segment of SERCA2b is shown (hatched). The consensus N-linked glycosylation motif is underlined, and the mutated residue N1036A is indicated in bold. (b) Comparison of Ca2+ wave activity in two oocytes overexpressing SERCA2bN1036A (top) or SERCA2bN1036A + ΔC (bottom). (c) The left histogram shows percent of oocytes exhibiting repetitive Ca2+ oscillations when SERCA2bN1036A is expressed alone or with ΔC. Of those oocytes that displayed repetitive Ca2+ oscillations, no significant differences were found in either interwave period (middle histogram) or in decay time (right histogram) between oocytes coexpressing ΔC with SERCA2bN1036A and control oocytes overexpressing SERCA2bN1036A alone. These results are similar to those observed for SERCA2a and SERCA2a + ΔC-overexpressing oocytes (see Fig. 4 b). (d) Western blot analysis demonstrates overexpression of ΔC in fractions from SERCA2bN1036A + ΔC oocytes (lane 1). No detectable CRT product was observed in extracts from control oocytes (H2O replacing mRNA) (lane 2). The membrane was probed with the anti-CRT KDEL primary Ab from Fig. 4 c. Image published in: John LM et al. (1998) Image reproduced on Xenbase with permission of the publisher and the copyright holder. Creative Commons Attribution-NonCommercial-ShareAlike license Larger Image Printer Friendly View

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