Nuclear pore complexes (NPCs) are large proteinaceous channels embedded in the 
nuclear envelope (NE), through which exchange of molecules between the nucleus 
and cytosol occurs. Biogenesis of NPCs is complex and poorly understood. In 
particular, almost nothing is known about how NPCs are anchored in the NE. Here, 
we characterize vertebrate NDC1--a transmembrane nucleoporin conserved between 
yeast and metazoans. We show by RNA interference (RNAi) and biochemical 
depletion that NDC1 plays an important role in NPC and NE assembly in vivo and 
in vitro. RNAi experiments suggest a functional link between NDC1 and the 
soluble nucleoporins Nup93, Nup53, and Nup205. Importantly, NDC1 interacts with 
Nup53 in vitro. This suggests that NDC1 function involves forming a link between 
the NE membrane and soluble nucleoporins, thereby anchoring the NPC in the 
membrane.