Essential nucleoporins Nup98 and Nup96 are coded by a single open reading frame, and produced by autopeptidase cleavage. The autocleavage site of Nup98-Nup96 is highly conserved in a wide range of organisms. To understand the importance of autocleavage, we examined a mutant that produces the Nup98-Nup96 joint molecule as a sole protein product of the nup189 (+) gene in the fission yeast Schizosaccharomyces pombe. Cells expressing only the joint molecule were found to be viable. This result indicates that autocleavage of Nup98-Nup96 is dispensable for cell growth, at least under normal culture conditions in S. pombe.
Keywords: Alternative splicing; FG nup; Fission yeast; GLFG repeat, Gly-Leu-Phe-Gly repeat; NE, nuclear envelope; NPC, nuclear pore complex; Nuclear pore complex; Nucleoporins; Nup107-160 complex.