Pharmacological manipulation of lysosome membrane integrity or ionic movements is a key strategy for probing lysosomal involvement in cellular processes. However, we have found an unexpected inhibition of store-operated Ca²⁺ entry (SOCE) by these agents. Dipeptides [glycyl-L-phenylalanine 2-naphthylamide (GPN) and L-leucyl-L-leucine methyl ester] that are inducers of lysosomal membrane permeabilization (LMP) uncoupled endoplasmic reticulum Ca²⁺-store depletion from SOCE by interfering with Stim1 oligomerization and/or Stim1 activation of Orai. Similarly, the K⁺/H⁺ ionophore, nigericin, that rapidly elevates lysosomal pH, also inhibited SOCE in a Stim1-dependent manner. In contrast, other strategies for manipulating lysosomes (bafilomycin A1, lysosomal re-positioning) had no effect upon SOCE. Finally, the effects of GPN on SOCE and Stim1 was reversed by a dynamin inhibitor, dynasore. Our data show that lysosomal agents not only release Ca²⁺ from stores but also uncouple this release from the normal recruitment of Ca²⁺ influx.

溶酶体膜完整性或离子运动的药理学操作是探索溶酶体参与细胞过程的关键策略。然而，我们发现这些药剂对存储操作的 Ca ²⁺进入 (SOCE)有意外的抑制作用。二肽 [甘氨酰-L-苯丙氨酸 2-萘基酰胺 (GPN) 和 L-亮氨酰-L-亮氨酸甲酯] 是溶酶体膜透化 (LMP) 的诱导物，通过干扰 Stim1 寡聚化，从 SOCE 中分离出内质网 Ca ²⁺ -store 消耗和/或 Orai 的 Stim1 激活。同样，K ⁺ /H ⁺快速升高溶酶体 pH 值的离子载体尼日利亚菌素也以 Stim1 依赖性方式抑制 SOCE。相比之下，操纵溶酶体的其他策略（巴弗洛霉素 A1，溶酶体重新定位）对 SOCE 没有影响。最后，GPN 对 SOCE 和 Stim1 的影响被动力蛋白抑制剂 dynasore 逆转。我们的数据显示，溶酶体试剂不仅从储存中释放 Ca ²⁺，而且还将这种释放与 Ca ²⁺流入的正常募集分离。