Abnormal expression of proteins involved in Ca²⁺ signaling in the patients. Platelets isolated from 3 healthy donors (C1-C3) and the 2 patients P1 and P2 were treated for simultaneous isolation of total lysate proteins and RNA. (A) Proteins were subjected to SDS-PAGE and WB using the isoform-specific antibodies indicated to detect PMCA, InsP3-R, and SERCA-type proteins as well as β3 and calreticulin (internal controls). In this figure and Figures 6, 7, the size of proteins is given in kilodaltons. (B) The intensity of the bands was quantified by densitometry and the mean values obtained for the 3 healthy donors were arbitrarily taken as 100%. The mean ± SD values (n = 8) of relative intensity (normalized to calreticulin) are shown in arbitrary units. ^*P < .01 compared with values from healthy donors. (C) Total RNA was subjected to specific RT-PCR to detect PMCA-, InsP3-R- and SERCA-RNA species, as well as GAPDH (internal control). Numbers indicate the sizes of PCR products in base pairs (bp). (D) The intensity of the bands was quantified as in panel B, except that the mean values (n = 6-10) of relative intensity were normalized to GAPDH. ^*P < .01 compared with values from healthy donors.