Filaments assembly of ectopically expressed Caenorhabditis elegans lamin within Xenopus oocytes

Lamins: the structure and protein complexes

“…Using minimal purification steps on physically isolated nuclear envelopes that are free of chromatin and other adhering material, cryo-electron tomography was applied. These experiments revealed that Ce-lamin assembles into flexible protofilaments that interacts with each other and exhibit a diameter of 5-6 nm ( Figure 1B and C) [17 ]. These data show that protofilaments are the basic assembly units in vivo and that they can assemble into thicker, higher order, filaments.…”

Structural and physiological phenotypes of disease-linked lamin mutations in C. elegans

“…Seminal studies by Aebi et al revealed that lamins in the Xenopus germinal vesicle assemble into a network of 10-nm filaments beneath the INM (Aebi et al, 1986;Goldberg et al, 2008;Grossman et al, 2011). However, the limitation of this model is that it has not allowed the study of lamin structures in somatic cells, which remains largely unknown (Prokocimer et al, 2009).…”

Lamins at the crossroads of mechanosignaling

“…Based on the ability of lamins to form heterodimers in vitro (Schirmer et al 2001), it was assumed that B-and A-type lamins can form heteropolymers also in vivo. However several recent studies, including fluorescence resonance energy transfer and superresolution microscopy analyses, and the expression of various lamin isoforms in Xenopus oocyte nuclei clearly revealed independent but interconnected networks of A-and B-type lamins (Goldberg et al 2008;Schermelleh et al 2008;Shimi et al 2008;Kolb et al 2011;Grossman et al 2012). These data support a model in which the farnesylated B-type lamins, especially lamin B1, form a more regular network closely associated with the INM and the nuclear pore complexes (NPCs) while the A-type lamins form more irregular meshworks on top of the lamin B structures.…”