Expression of IP3R subtypes in HEK cells. Expression of IP3R subtypes in HEK cells. (A) Western blots using IP3R subtype-selective antibodies (Ab1, Ab2, Ab3) or a common antibody (AbC). Lanes were loaded with 20, 40, 80 or 120 μg protein for WT cells, and with 80 or 120 μg for other cell lines. Molecular mass markers (kDa) are shown. Arrowheads indicate IP3R bands used for quantification. (B–D) Summary of results (in %, mean±s.e.m., n=5) show relative expression of IP3R subtypes in WT cells (B), determined by calibrating bands identified by Ab1, Ab2 or Ab3 to bands identified by AbC in cell lines expressing single IP3R subtypes; IP3R expression (in %) in cell lines expressing single subtypes relative to the same IP3R subtype in WT cells (C); and total number of IP3Rs (in %) expressed in each cell line relative to number in WT (D), by comparing intensities of protein bands recognised by AbC. In C, the asterisk (*) denotes values where 95% confidence interval does not include 100%. No significant differences (P<0.05) were observed between values in D. Stefania Mataragka, and Colin W. Taylor J Cell Sci 2018;131:jcs220848 © 2018. Published by The Company of Biologists Ltd