NIC96P IS REQUIRED FOR NUCLEAR-PORE FORMATION AND FUNCTIONALLY INTERACTS WITH A NOVEL NUCLEOPORIN, NUP188P

The amino-terminal domain of Nic96p physically interacts with the Nsp1 p complex which is involved in nucleocytoplasmic transport. Here we sh ow that thermosensitive mutations mapping in the central domain of Nic 96p inhibit nuclear pore formation at the nonpermissive temperature. F urthermore, the carboxyterminal domain of Nic96p functionally interact s with a novel nucleoporin Nup188p in an allele-specific fashion, and when ProtA-Nup188p was affinity purified, a fraction of Nic96p was fou nd in physical interaction. Although NUP188 is not essential for viabi lity, a null mutant exhibits striking abnormalities in nuclear envelop e and nuclear pore morphology. We propose that Nic96p is a multivalent protein of the nuclear pore complex linked to several nuclear pore pr oteins via its different domains.