Phospholipase Cδ₁ associates with importin β1 and translocates into the nucleus in a Ca²⁺-dependent manner

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• 作者：Masashi Okada ; Takayuki Ishimoto ; Yoko Naito ; Hajime Hirata and Hitoshi Yagisawa
• 关键词：Phospholipase C ; Importin ; Ca²⁺ ; Nuclear localization ; Ionomycin
• 刊名：FEBS Letters
• 出版年：2005
• 期刊代码：70_00145793
• 类别：bio
• 出版时间：2005
• 卷：579
• 期：22
• 页码：4949-4954
• 文件大小：288 K

摘要

Phospholipase C (PLC)δ₁ shuttles between the nucleus and the cytoplasm. Here, we demonstrate that treatment of MDCK cells and PC12 cells with ionomycin causes nuclear accumulation of ectopically expressed and endogenous PLCδ₁, respectively, suggesting that signals that increase [Ca²⁺]_i trigger nuclear translocation. To clarify the molecular mechanisms involved in this translocation, we have examined whether PLCδ₁ binds with importins. PLCδ₁ interacted with importin β1 in a Ca²⁺-dependent manner in vitro even in the absence of importin α. A PLCδ₁ mutant E341A, which lacks Ca²⁺-binding to the catalytic core, did not show this interaction at any physiological Ca²⁺ concentration and did not translocate into the nucleus after ionomycin treatment when expressed in MDCK cells. These results suggested that the nuclear import of PLCδ₁ is mediated by its Ca²⁺-dependent interaction with importin β1.