Phosphatidylinositol 4,5-bisphosphate directs spermatid cell polarity and exocyst localization in Drosophila.
Phosphatidylinositol 4,5-bisphosphate directs spermatid cell polarity and exocyst localization in Drosophila.
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DOI：
10.1091/mbc.e09-07-0582
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发表时间：
2010-05-01
影响因子：
3.3
通讯作者：
Brill JA
中科院分区：
文献类型：
--
作者：
Fabian L;Wei HC;Rollins J;Noguchi T;Blankenship JT;Bellamkonda K;Polevoy G;Gervais L;Guichet A;Fuller MT;Brill JA
这项研究确定磷酸肌醇作为精子细胞极性的关键调节因子。果蝇精子细胞的极化和伸长通过Sktl局部合成PIP 2来调节，PIP 2驱动外囊复合物的极化定位以促进靶向膜递送和伸长精子细胞囊的极化。在精子发生过程中，黑腹果蝇精子细胞在相互连接的包囊中协调它们的伸长，包囊变得高度极化，细胞核定位于一端，精子尾部生长发生在另一端。值得注意的是，我们对驱动精子细胞极性和伸长的信号知之甚少。在这里，我们确定磷酸肌醇作为这些过程的关键监管机构。质膜磷脂酰肌醇4，5-二磷酸（PIP 2）通过PIP 2磷酸酶SigD的低水平表达或PIP 2生物合成酶Skittles（Sktl）的突变而减少，导致精子细胞包囊中的显著缺陷，其变成双极并且不能完全伸长。极性的缺陷从伸长的最早阶段就很明显，表明磷酸肌醇是建立极性所必需的。Skt 1和PIP 2与外囊复合体一起定位于囊的生长端。引人注目的是，当PIP 2水平降低时，外囊变得完全离域，并且Sktl的过表达恢复外囊定位和精子细胞囊极性。此外，外囊是极性所必需的，因为外囊亚基Sec 8的功能部分丧失导致双极囊。我们的数据与PIP 2的局部合成招募外囊以促进靶向膜递送和延长囊的极化的机制一致。
This study identifies phosphoinositides as key regulators of spermatid cell polarity. Polarization and elongation of spermatids in Drosophila are regulated through local synthesis of PIP2 by Sktl, which drives polarized localization of the exocyst complex to promote targeted membrane delivery and polarization of the elongating spermatid cysts. During spermiogenesis, Drosophila melanogaster spermatids coordinate their elongation in interconnected cysts that become highly polarized, with nuclei localizing to one end and sperm tail growth occurring at the other. Remarkably little is known about the signals that drive spermatid polarity and elongation. Here we identify phosphoinositides as critical regulators of these processes. Reduction of plasma membrane phosphatidylinositol 4,5-bisphosphate (PIP2) by low-level expression of the PIP2 phosphatase SigD or mutation of the PIP2 biosynthetic enzyme Skittles (Sktl) results in dramatic defects in spermatid cysts, which become bipolar and fail to fully elongate. Defects in polarity are evident from the earliest stages of elongation, indicating that phosphoinositides are required for establishment of polarity. Sktl and PIP2 localize to the growing end of the cysts together with the exocyst complex. Strikingly, the exocyst becomes completely delocalized when PIP2 levels are reduced, and overexpression of Sktl restores exocyst localization and spermatid cyst polarity. Moreover, the exocyst is required for polarity, as partial loss of function of the exocyst subunit Sec8 results in bipolar cysts. Our data are consistent with a mechanism in which localized synthesis of PIP2 recruits the exocyst to promote targeted membrane delivery and polarization of the elongating cysts.
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影响因子：
3.3
作者：
Giansanti, MG;Farkas, RM;Gatti, M
通讯作者：
Gatti, M
影响因子：
9.8
作者：
Hense, Winfried;Baines, John F.;Parsch, John
通讯作者：
Parsch, John
影响因子：
64.8
作者：
Di Paolo, G;Pellegrini, L;De Camilli, P
通讯作者：
De Camilli, P
影响因子：
7.8
作者：
Beronja, Slobodan;Laprise, Patrick;Papoulas, Ophelia;Pellikka, Milena;Sisson, John;Tepass, Ulrich
通讯作者：
Tepass, Ulrich
影响因子：
7.8
作者：
HOYLE, HD;RAFF, EC
通讯作者：
RAFF, EC