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Phospholiase C‐eta1 is activated by intracellular Ca2+ mobilization and enhances GPCRs‐mediated signaling
Author(s) -
Kim Jung Kuk,
Choi Jung Woong,
Lim Seyoung,
Ryu Sung Ho,
Suh PannGhill
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb177
Subject(s) - gene knockdown , g protein coupled receptor , microbiology and biotechnology , ionomycin , signal transduction , phosphorylation , phospholipase c , intracellular , chemistry , small interfering rna , biology , apoptosis , biochemistry , rna , gene
Phospholipase C‐η1 (PLC‐η1) is the most recently identified PLC isotype and mainly expressed in nerve tissue. In the present study, we first report that PLC‐η1 acts as a signal amplifier in G protein‐coupled receptors (GPCRs)‐mediated PLC/Ca 2+ signaling in neuronal cell. RNA interference‐mediated knockdown of endogenous PLC‐η1 reduced LPA, BK, and PACAP‐induced PLC activity in mouse neuroblastoma Neuro2A (N2A) cells, indicating that activation of PLC‐η1 is regulated by GPCRs‐mediated signaling. Interestingly, ionomycin‐induced PLC activity was significantly decreased in PLC‐η1 knockdown, but not in PLC‐η2 knockdown N2A cells. In addition, the IP 3 receptor blocker, 2‐APB was found to inhibit LPA‐induced PLC activity in control, but it had no more inhibitory effect in PLC‐η1 knockdown N2A cells, suggesting the pivotal role of intracellular Ca 2+ mobilization in PLC‐η1 activation. Moreover, LPA‐induced ERK1/2 phosphorylation and downstream target gene, krox‐24, expression was significantly decreased by PLC‐η1 knockdown. Finally, we found that 2‐APB inhibited both ERK1/2 phosphorylation and krox‐24 expression only in control, but it had no more inhibitory effect in PLC‐η1 knockdown N2A cells. Taken together, our results strongly suggest that PLC‐η1 is secondarily activated via Ca 2+ mobilized from ER and therefore amplifies GPCRs‐mediated signaling in N2A cells. This study was supported by the National Research Foundation of Korea Grant funded by the Korean Government (KRF‐2007‐341‐C00027)