Opposing effects of protein kinase A and C on capacitative calcium entry into HL-60 promyelocytes

Abstract

ABSTRACT. Treatment of HL-60 cells with thapsigargin, a microsomal Ca 2ϩ /ATPase inhibitor, led to depletion of intracellular calcium stores followed by capacitative calcium entry. Stimulation of adenylyl cyclase with forskolin enhanced thapsigargin-induced Ca 2ϩ influx. The forskolin effect was confirmed by enhanced fluorescence quenching induced by Mn 2ϩ entry into fura-2 loaded cells. 1,9-Dideoxy-forskolin, an inactive analog of forskolin, did not affect capacitative calcium entry. On the other hand, phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, inhibited thapsigargin-induced Ca 2ϩ entry. Histamine and prostaglandin E 2 (PGE 2 ) elevated intracellular adenosine 3Ј:5Ј-cyclic monophosphate (cAMP) levels and enhanced the thapsigargin-induced capacitative calcium entry. Incubation with N- [2-(p-bromocynnamylamino)ethyl]-5-isoquinolinesulfonamide (H89), an inhibitor of protein kinase A (PKA), blocked the forskolin effect, and GF109203X, an inhibitor of protein kinase C (PKC), blocked the phorbol 12-myristate 13-acetate effect. The results suggest that protein kinase A regulates capacitative calcium entry positively, but that protein kinase C regulates Ca 2ϩ influx negatively. Furthermore, after differentiation of HL-60 promyelocytes with dimethylsulfoxide to granulocytes, the inhibitory effect of phorbol 12-myristate 13-acetate became more pronounced, whereas the stimulatory effect of prostaglandin E 2 did not change. This result suggests that the regulation of capacitative calcium entry by protein kinase C and protein kinase A develops differently during differentiation. BIOCHEM PHARMACOL 56;5:561-567, 1998. © 1998 Elsevier Science Inc. KEY WORDS. protein kinase A; protein kinase C; capacitative calcium entry; HL-60 cells Elevation of cytosolic IP 3 † levels after stimulation of receptors linked to the phosphoinositide-signaling pathway triggers Ca 2ϩ release from intracellular calcium stores. The depletion of these calcium stores induces calcium influx through CRACs in the plasma membrane, thereby refilling the empty calcium stores [1][2][3]. This mechanism has been termed "capacitative calcium entry." The relation between calcium stores and CRAC thus suggests the involvement of a diffusable messenger [4,5].Little is known about the regulatory mechanism of capacitative calcium entry, but the involvement of cytosolic factors has been reported. A recent study of Jurkat leukemic T lymphocytes revealed that a feedback effect of Ca 2ϩ inhibits CRAC [6]. It has also been suggested that tyrosine kinase and phosphatase [7,8] as well as intracellular adenine-guanine nucleotide levels [9] regulate capacitative calcium entry. In addition, small GTP-binding protein (G-protein) has been implicated in capacitative calcium entry into rat basophil leukemia cells [10] and mouse lachrymal acinar cells [11]. Moreover, heterotrimeric G-protein is reported to be involved in the regulation of CRAC in HL-60 granulocytes [12] and Xenopus oocytes [13,14] with a direct or indirect mode of action. Indirect regul...

Role of nonselective cation channels in spontaneous and protein kinase A-stimulated calcium signaling in pituitary cells

“…This finding does not necessarily support the hypothesis that PKA is responsible for this effect because H89 in a 10 M concentration also inhibits S6K1 (100%), ROCK-II (100%), MSK1 (97%), PKB␣ (83%), AMPK (81%), CHK1 (79%), SGK (75%), and PHK (49%) (6). Here, we have also shown that the application of H89 causes a transient stimulation of Ca 2ϩ influx, a finding that is consistent with observations in other cell types (31) and indicates the nonspecific effect of this compound. Experiments with Rp-cAMPs also showed that spontaneous electrical activity in pituitary cells is not affected by the inhibition of PKA, whereas an 8-Br-cAMPstimulated increase in the frequency of APs was abolished in the presence of this compound.…”

Chlorpromazine inhibits store‐operated calcium entry and subsequent noradrenaline secretion in PC12 cells

“…The Mn 2+ quenching assay was performed as described by Song et al . (1998 ) to measure the influx of Ca 2+ from the extracellular space.…”

“…Mn 2+ quenching of fura-2 fluorescence The Mn 2+ quenching assay was performed as described by Song et al (1998) to measure the in¯ux of Ca 2+ from the extracellular space. Brie¯y, fura-2-loaded cells (5610 6 cells ml 71 ) were placed into a quartz cuvette in a thermostatically controlled cell holder at 378C and continuously stirred.…”

Characterization and regulation of rat microglial Ca2+ release-activated Ca2+ (CRAC) channel by protein kinases

“…Several reports have shown that cAMP-dependent protein kinase (PKA) and protein kinase C (PKC) regulate capacitative Ca 2ϩ entry (Parekh and Penner, 1995;Song et al, 1998). In order to test the modulatory role of PKA on CRAC channel, we perfused the external solution with the solution containing membranepermeant analogue of cAMP, dibutyryl cAMP.…”

“…Several studies propose that PKC and PKA are implicated in the modulation of CRAC channels in various cells. PKC inhibits Ca 2ϩ influx through CRAC channel in HL-60 cells (Montero et al, 1993;Song et al, 1998) and rat basophilic leukemia cells (Parekh and Penner, 1995). When we compared the PDBu effects on CRAC channel in the presence and absence of staurosporine, the activation of PKC reduces the current.…”