Velez-Aguilera Griselda, Ossareh-Nazari Batool, Van Hove Lucie, Joly Nicolas, Pintard Lionel
Université Paris cité, CNRS, Institut Jacques Monod, F-75013, Paris, France.
Elife. 2022 Mar 8;11:e75382. doi: 10.7554/eLife.75382.
Previously, we reported that the Polo-like kinase PLK-1 phosphorylates the single lamin (LMN-1) to trigger lamina depolymerization during mitosis. We showed that this event is required to form a pronuclear envelope scission event that removes membranes on the juxtaposed oocyte and sperm pronuclear envelopes in the zygote, allowing the parental chromosomes to merge in a single nucleus after segregation (Velez-Aguilera et al., 2020). Here, we show that cortical microtubule pulling forces contribute to pronuclear envelopes scission by promoting mitotic spindle elongation, and conversely, nuclear envelopes remodeling facilitates spindle elongation. We also demonstrate that weakening the pronuclear envelopes via PLK-1-mediated lamina depolymerization, is a prerequisite for the astral microtubule pulling forces to trigger pronuclear membranes scission. Finally, we provide evidence that PLK-1 mainly acts via lamina depolymerization in this process. These observations thus indicate that temporal coordination between lamina depolymerization and mitotic spindle elongation facilitates pronuclear envelopes scission and parental genomes unification.
此前，我们报道过，Polo样激酶PLK-1使单个核纤层蛋白（LMN-1）磷酸化，从而在有丝分裂期间触发核纤层解聚。我们发现，这一事件是形成原核包膜切断事件所必需的，该事件会去除受精卵中并列的卵母细胞和精子原核包膜上的膜，使亲代染色体在分离后合并到一个细胞核中（Velez-Aguilera等人，2020年）。在此，我们表明，皮质微管拉力通过促进有丝分裂纺锤体伸长，有助于原核包膜切断，反之，核包膜重塑促进纺锤体伸长。我们还证明，通过PLK-1介导的核纤层解聚削弱原核包膜，是星状微管拉力触发原核膜切断的先决条件。最后，我们提供证据表明，PLK-1在此过程中主要通过核纤层解聚发挥作用。因此，这些观察结果表明，核纤层解聚与有丝分裂纺锤体伸长之间的时间协调，有助于原核包膜切断和亲代基因组统一。
