Isozyme-specific activation and its physiological function of PIP5K, an enzyme involved in lipid-signaling.

磷脂激酶PIP5K通过其产物PIP2（多效性脂质信使）在多种细胞功能中发挥重要作用。迄今为止，已鉴定出三种哺乳动物PIP 5K同工酶α、β和γ。以前，我们已经确定了小GTd6 Arf 6作为PIP5K的直接激活剂。在本研究中，我们检测了Arf 6对PIP5K的同工酶特异性激活，并证明Arf 6对PIP5K γ的激活是通过N-末端介导的PIP5K γ的"分子内掩蔽"来调节的。

The phospholipid kinase PIP5K plays important roles in a wide variety of cellular functions through its product PIP2, the pleiotropic lipid messenger. To date, three mammalian PIP5K isozymes, α, β and γ have been identified. Previously, we have identified the small GTPase Arf6 as the direct activator of PIP5K. In the present study, we examined isozyme-specific activation of PIP5K by Arf6 and demonstrated that the activation of PIP5Kγ by Arf6 is regulated through the N-terminal mediated 'intra-molecular masking' of PIP5Kγ.