Functional interaction studies of different transmembrane proteins, activities occurring in the pore membrane and in the inner nuclear membrane

Aim: The overall aim of my research has been to investigate protein‐protein interactions of nuclear envelope proteins. One specific aim has been to study the effect of mitotic phosphorylation on binding of the pore membrane protein gp210 to the nuclear pore complex. The second specific aim has been to identify binding partners to the INM protein Samp1.

Conclusions: Paper I) Phosphomimetic substitution of Ser1880 to Glu of gp210 compromises its interaction with the NPC; Phosphomimetic substitution of Ser1880 to Glu of gp210 hinders its recruitment to the reforming NPC; and The results support a model where phosphorylation plays a direct role in the disassembly the NPC during mitosis.

Paper II) We have developed a cross‐link immunoprecipitation protocol for transmembrane proteins in vivo; Using crosslink immunoprecipitation we show that Samp1 interacts with the INM protein Emerin in vivo; Using crosslink immunoprecipitation we show that Sun1 and Samp1 interact in vivo; and Using crosslink immunoprecipitation we show an in vivo interaction between Ran and Samp1 at the INM.

List of scientific papers

I. Phosphomimetic mutation of the mitotically phosphorylated serine 1880 compromises the interaction of the transmembrane nucleoporin gp210 with the nuclear pore complex. Onischenko EA, Crafoord E, Hallberg E. Exp Cell Res. 2007 Jul 15; 313(12):2744-51.
https://doi.org/10.1016/j.yexcr.2007.05.011

II. In vivo interaction between the transmembrane inner nuclear membrane protein Samp1 and LINC complex proteins. Crafoord, E. [Manuscript]