Merima Beganovic, Westminster College
Molecular Biology
Nuclear Pore Complexes (NPC) create aqueous channels embedded in the nuclear envelope and are made from a network of proteins called nucleoporins (nups). The nucleoporin Nup153 has previously been found to be required for proper assembly of the nuclear lamina. In this study, a fragment of Nup153 was overexpressed in order to impede Nup153 function in T-Rex HeLa cells. After inducing the expression of the dominant negative fragment, I examined the localization of lamins A, B1 and B2, as well as SUN1, Emerin, and BiP, three proteins that mark cell membrane compartments. Lamins B1, B2, SUN1, and Emerin were found to mislocalize to the cytoplasm of the cells, and colocalization among the proteins was observed. Lamin A also had an abnormal phenotype unlike that seen with the B lamins, but indicative of a problem with integration of Lamin A into the nuclear lamina. Colocalization of the various lamin isoforms with membrane proteins such as SUN1 and Emerin indicates a problem with membrane assembly. The distinct localization of BiP, however, suggests that there is a “nuclear-like” membrane in the cytoplasm that either does not incorporate normally into the nuclear envelope as it forms or is newly-recruited to mislocalize the lamin proteins.