Abstract

We have previously isolated three synthetic lethal mutants from Schizosaccharomyces pombe in order to identify mutations in the genes that are functionally linked to spmex67 with respect to mRNA export. A novel rsm1 gene was isolated by complementation of the growth defect in one of the synthetic lethal mutants, SLMex1. The rsm1 gene contains no introns and encodes a 296 amino-acid-long protein with the RING finger domain, a C3HC4 in the N-terminal half. The [delta]rsm1 null mutant is viable, but it showed a slight poly(A)^+ RNA accumulation in the nucleus. Also, the combination of [delta]rsm1 and [delta]spmex67 mutations confers synthetic lethality that is accompanied by the severe poly(A)^+ RNA export defect. These results suggest that rsm1 is involved in mRNA export from the nucleus.

• Keywords: rsm1; mex67; synthetic lethality; mRNA export; Schizosaccharomyces pombe