Difference in Ca2+ oscillation-inducing activity and nuclear translocation ability of PLCZ1, an egg-activating sperm factor candidate, between mouse, rat, human, and medaka fish
Difference in Ca2+ oscillation-inducing activity and nuclear translocation ability of PLCZ1, an egg-activating sperm factor candidate, between mouse, rat, human, and medaka fish
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DOI：
10.1095/biolreprod.108.067801
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发表时间：
2008-06-01
影响因子：
3.6
通讯作者：
Miyazaki, Shunichi
中科院分区：
文献类型：
--
作者：
Ito, Masahiko;Shikano, Tomohide;Miyazaki, Shunichi
小鼠磷脂酶C zeta 1（PLCZ 1）是一种强有力的精子激活因子候选者，当通过cRNA注射表达时，可诱导Ca 2+振荡并积累到形成的原核（PN）中。这些活动之间进行了比较，小鼠和人类PLCZ 1，新克隆的大鼠PLCZ 1，青鳉鱼PLCZ 1。这四个物种的PLCZ 1蛋白具有近似同源的核定位信号序列。然而，核转位能力是有缺陷的大鼠，人类和青鳉PLCZ 1在小鼠卵中表达。大鼠PLCZ 1不能进入大鼠PN，而小鼠PLCZ 1可以。小鼠和人PLCZ 1易位到用cDNA转染的COS-7细胞的细胞核中。青鳉PLCZ 1在细胞核内几乎没有聚集，大鼠PLCZ 1在细胞核内几乎没有分布。所有的PLCZ 1蛋白质，包括鱼，都可以诱导小鼠卵中的Ca 2+振荡，但活性的顺序是人>>小鼠>青鳉>>大鼠，从诱导Ca 2+尖峰的最小RNA浓度估计。人PLCZ 1的Ca 2+振荡持续远远超过PN形成时间（TIN），而小鼠PLCZ 1的Ca 2+振荡在TIN之前稍有停止。高频率的Ca 2+尖峰过表达的大鼠PLCZ 1停止远TIN之前，可能是通过反馈抑制。Ca 2+振荡受精的大鼠卵子停止在TIN，尽管有缺陷的核转位的大鼠PLCZ 1。因此，PLCZ 1螯合到PN参与终止钙21振荡在间期的小鼠胚胎，但并不总是在其他哺乳动物，特别是在大鼠胚胎。
Mouse phospholipase C, zeta 1 (PLCZ1), a strong candidate of egg-activating sperm factor, induces Ca2+ oscillations and accumulates into formed pronucleus (PN) when expressed by cRNA injection. These activities were compared among mouse and human PLCZ1, newly cloned rat Plcz1, and medaka fish plcz1. The PLCZ1 proteins of the four species have an approximately homologous sequence of nuclear localization signal. However, the nuclear translocation ability was defective in rat, human, and medaka PLCZ1 expressed in mouse eggs. Rat PLCZ1 could not enter rat PN, whereas mouse PLCZ1 could. Mouse and human PLCZ1 translocated into the nucleus of COS-7 cells transfected with cDNA. There was little medaka PLCZ1 accumulated in the nucleus, and rat PLCZ1 was never located in the nucleus. All PLCZ1 proteins including fish could induce Ca2+ oscillations in mouse eggs, but the activity was variable in the order of human >> mouse > medaka >> rat, estimated from minimal RNA concentration to induce Ca2+ spikes. Ca2+ oscillations by human PLCZ1 continued far beyond the time of PN formation (TIN), whereas those by mouse PLCZ1 ceased slightly before TIN. High-frequency Ca2+ spikes by overexpressed rat PLCZ1 stopped far before TIN, possibly by feedback inhibition. Ca2+ oscillations by fertilization of rat eggs stopped at TIN, despite defective nuclear translocation of rat PLCZ1. Thus, PLCZ1 sequestration into PN participates in termination of Ca 21 oscillations at the interphase of mouse embryos but does not always operate in other mammals, notably in rat embryos.