Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
Protein-protein interactions between the nuclear lamins are responsible for the assembly of the nuclear lamina, a meshwork of intermediate filaments associated with the nuclear envelope inner membrane. We have used the yeast two-hybrid system to examine the interactions between the predominant human nuclear lamins expressed as GAL4 fusion proteins in Saccharomyces cerevisiae. Lamin A, prelamin A, lamin B1, and lamin C were able to form homodimers as well as heterodimers. Analysis of the different structural domains of lamin B1 demonstrated that the second half of coil 2 of the rod domain was necessary for the formation of the most stable homodimers. The results show that the yeast two-hybrid system can be used to study the interactions between structural proteins and their domains.