Fig. 2. Schematic representation of reporter gene constructs and results of luciferase assays, showing the impact of miR-34a-5p on target genes related to store-operated Ca²⁺ entry.

a–d 3′-UTR sequences of ITPR2 (inositol 1,4,5-trisphosphate receptor type 2), CAMLG (calcium-modulating ligand), STIM1 (stromal interaction molecule 1), and ORAI3 (ORAI calcium release-activated calcium modulator 3) were cloned into pMIR-RNL-TK reporter plasmids. The positions of the predicted miR-34a-5p-binding sites within the cloned 3′-UTR reporter constructs are illustrated and denoted. Mutated binding sites are shown underlined. e–h Relative luciferase activity [%] is shown for empty reporter plasmids (pMIR-RNL-TK), as well as wild type and mutated (mut) 3′-UTR-containing constructs. HEK293T cells were co-transfected with control (pSG5) or miR-34a expression plasmids. Luciferase activities were measured 48 h after transfection. Results are shown as means of four independent experiments with corresponding standard errors (SEM). Statistical evaluation was performed using Student’s t-test. A normal distribution of the data was assumed. (*p ≤ 0.05, **p < 0.01, ***p < 0.001; statistical comparison between wild-type 3′-UTR and mutated 3′-UTR containing two miR-34a-5p-binding sites was only performed for double mutated constructs)