ARF6 regulates a plasma membrane pool of phosphatidylinositol(4,5)bisphosphate required for regulated exocytosis.
ARF6 regulates a plasma membrane pool of phosphatidylinositol(4,5)bisphosphate required for regulated exocytosis.
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DOI：
10.1083/jcb.200212142
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发表时间：
2003-08-18
期刊：
影响因子：
--
通讯作者：
Martin TF
中科院分区：
文献类型：
--
作者：
Aikawa Y;Martin TF
ADP-核糖基化因子（ARF）6调节许多细胞类型中的内体质膜运输，但也被认为在神经内分泌细胞中的Ca 2+依赖性致密核心囊泡（DCV）胞吐中发挥作用。在目前的工作中，组成型活性GTP酶缺陷型ARF 6 Q67 L突变体在PC 12细胞中的表达被发现抑制Ca 2+依赖的DCV胞吐。胞吐作用的抑制伴随着ARP 167 L、磷脂酰肌醇4，5-二磷酸（PIP 2）和磷脂酰肌醇4-磷酸5-激酶I型（PIP 5 KI）在内体膜上的积累以及它们从质膜的相应消耗。在渗透性细胞重建研究中直接证明了PIP 2和PIP 5 K从质膜的消耗导致DCV胞吐的抑制，其中过表达或添加PIP 5 KI γ恢复了Ca 2+依赖性胞吐。在表达ARF 6 Q67 L的渗透性细胞中，胞吐作用的恢复出人意料地表现出Ca 2+依赖性，这归因于PIP 5 K的去磷酸化和活化。Ca 2+增加和去磷酸化刺激PIP 5 KI γ与ARF 6的结合。结果揭示了Ca 2+内流促进PIP 2的ARF 6依赖性合成增加的机制。我们的结论是，ARF 6通过调节PIP 5 K的活性，在钙依赖性DCV胞吐中发挥作用，PIP 2的一个重要的质膜池的合成。
ADP-ribosylation factor (ARF) 6 regulates endosomal plasma membrane trafficking in many cell types, but is also suggested to play a role in Ca2+-dependent dense-core vesicle (DCV) exocytosis in neuroendocrine cells. In the present work, expression of the constitutively active GTPase-defective ARF6Q67L mutant in PC12 cells was found to inhibit Ca2+-dependent DCV exocytosis. The inhibition of exocytosis was accompanied by accumulation of ARFQ67L, phosphatidylinositol 4,5-bisphosphate (PIP2), and the phosphatidylinositol 4-phosphate 5-kinase type I (PIP5KI) on endosomal membranes with their corresponding depletion from the plasma membrane. That the depletion of PIP2 and PIP5K from the plasma membrane caused the inhibition of DCV exocytosis was demonstrated directly in permeable cell reconstitution studies in which overexpression or addition of PIP5KIγ restored Ca2+-dependent exocytosis. The restoration of exocytosis in ARF6Q67L-expressing permeable cells unexpectedly exhibited a Ca2+ dependence, which was attributed to the dephosphorylation and activation of PIP5K. Increased Ca2+ and dephosphorylation stimulated the association of PIP5KIγ with ARF6. The results reveal a mechanism by which Ca2+ influx promotes increased ARF6-dependent synthesis of PIP2. We conclude that ARF6 plays a role in Ca2+-dependent DCV exocytosis by regulating the activity of PIP5K for the synthesis of an essential plasma membrane pool of PIP2.
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影响因子：
4.8
作者：
Galas, MC;Helms, JB;Bader, MF
通讯作者：
Bader, MF
DOI：
10.1083/jcb.200102098
发表时间：
2001-07-23
期刊：
The Journal of cell biology
影响因子：
--
作者：
Micheva KD;Holz RW;Smith SJ
通讯作者：
Smith SJ
影响因子：
4.8
作者：
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通讯作者：
Bader, MF
影响因子：
64.8
作者：
HAY, JC;MARTIN, TFJ
通讯作者：
MARTIN, TFJ
影响因子：
4.8
作者：
Barylko, B;Gerber, SH;Albanesi, JP
通讯作者：
Albanesi, JP