Dynein pulling forces on ruptured nuclei counteract lamin-mediated nuclear envelope repair mechanisms in vivo

Citations Over Time

Abstract

Abstract Recent work done exclusively in tissue culture cells revealed that the nuclear envelope (NE) undergoes ruptures leading to transient mixing of nuclear and cytoplasmic components. The duration of transient NE ruptures depends on lamins, however the underlying mechanisms and the relevance to in vivo events is not known. Here, we use C. elegans embryos to show that dynein forces that position nuclei increase the severity of lamin-induced NE ruptures in vivo . In the absence of dynein forces, lamin prevents nuclear-cytoplasmic mixing caused by NE ruptures. By monitoring the dynamics of NE rupture events, we demonstrate that lamin is required for a distinct phase in NE recovery that restricts nucleocytoplasmic mixing prior to the full restoration of NE rupture sites. We show that laser-induced puncture of the NE recapitulates phenotypes associated with NE recovery in wild type cells. Surprisingly, we find that embryonic lethality does not correlate with the incidence of NE rupture events suggesting that embryos survive transient losses of NE compartmentalization during early embryogenesis. In addition to presenting the first mechanistic analysis of transient NE ruptures in vivo , this work demonstrates that lamin controls the duration of NE ruptures by opposing dynein forces on ruptured nuclei to allow reestablishment of the NE permeability barrier and subsequent restoration of NE rupture sites.

Related Papers

• → Lamins A and C but Not Lamin B1 Regulate Nuclear Mechanics(2006)707 cited
• → Prelamin A and lamin A appear to be dispensable in the nuclear lamina(2006)249 cited
• → Concentration-dependent lamin assembly and its roles in the localization of other nuclear proteins(2014)80 cited
• → The Stability of the Nuclear Lamina Polymer Changes with the Composition of Lamin Subtypes According to Their Individual Binding Strengths(2004)81 cited
• → Nuclear shape is affected differentially by loss of lamin A, lamin C, or both lamin A and C(2023)5 cited