PIP2 Hydrolysis and Calcium Release Are Required for Cytokinesis in Drosophila Spermatocytes
PIP2 Hydrolysis and Calcium Release Are Required for Cytokinesis in Drosophila Spermatocytes
复制标题
DOI：
10.1016/j.cub.2005.06.060
复制
发表时间：
2005-08
期刊：
影响因子：
9.2
通讯作者：
Raymond Wong;I. Hadjiyanni;Ho-Chun Wei;G. Polevoy;Rachel M McBride;K. Sem;J. Brill
中科院分区：
文献类型：
--
作者：
Raymond Wong;I. Hadjiyanni;Ho-Chun Wei;G. Polevoy;Rachel M McBride;K. Sem;J. Brill
钙（Ca 2+）在胞质分裂中的作用是有争议的[1，2]，并且在分裂期间导致其释放的精确途径还没有很好地理解。通过三磷酸肌醇（IP 3）与IP 3受体（IP 3R）的结合，Ca 2+从细胞内储存中释放[3]，但尚未确定IP 3的前体磷脂酰肌醇4，5-二磷酸（PIP 2）在胞质分裂中的作用。在这里，使用表达PLCδ-PH-GFP的转基因果蝇，其特异性结合PIP 2 [4-6]，我们在分裂的果蝇精母细胞的质膜和卵裂沟中鉴定了PIP 2，并且我们确定这种磷脂是持续进入所需的，但不是胞质分裂的起始所需的。此外，通过抑制磷脂酶C，我们表明，PIP 2必须被水解，以保持分裂沟的稳定性。使用IP 3R拮抗剂和Ca 2+螯合剂研究IP 3R和Ca 2+在胞质分裂中的作用，我们证明了这两个因素都是卵裂沟稳定性所需的，尽管Ca 2+是卵裂平面规范和开沟起始所必需的。引人注目的是，为细胞提供Ca 2+消除了水解PIP 2的需要。因此，PIP 2、PIP 2水解和Ca 2+是这些细胞中胞质分裂正常进行所必需的。
The role of calcium (Ca2+) in cytokinesis is controversial [1, 2], and the precise pathways that lead to its release during cleavage are not well understood. Ca2+is released from intracellular stores by binding of inositol trisphosphate (IP3) to the IP3 receptor (IP3R) [3], yet no clear role in cytokinesis has been established for the precursor of IP3, phosphatidylinositol 4,5-bisphosphate (PIP2). Here, using transgenic flies expressing PLCδ-PH-GFP, which specifically binds PIP2 [4–6], we identify PIP2 in the plasma membrane and cleavage furrows of dividing Drosophila melanogaster spermatocytes, and we establish that this phospholipid is required for continued ingression but not for initiation of cytokinesis. In addition, by inhibiting phospholipase C, we show that PIP2 must be hydrolyzed to maintain cleavage furrow stability. Using an IP3R antagonist and a Ca2+chelator to examine the roles of IP3R and Ca2+in cytokinesis, we demonstrate that both of these factors are required for cleavage furrow stability, although Ca2+is dispensable for cleavage plane specification and initiation of furrowing. Strikingly, providing cells with Ca2+obviates the need to hydrolyze PIP2. Thus, PIP2, PIP2 hydrolysis, and Ca2+are required for the normal progression of cytokinesis in these cells.