Identification of novel suppressors for Mog1 implies its involvement in RNA metabolism, lipid metabolism and signal transduction.

Mog1 is conserved from yeast to mammal, but its function is obscure. We isolated yeast genes that rescued a temperature-sensitive death of S. cerevisiae Scmog1Delta, and of S. pombe Spmog1(ts). Scmog1Delta was rescued by Opi3p, a phospholipid N-methyltransferase, in addition to S. cerevisiae Ran-homologue Gsp1p, and a RanGDP binding protein Ntf2p. On the other hand, Spmog1(ts) was rescued by Cid13 that is a poly (A) polymerase specific for suc22(+) mRNA encoding a subunit of ribonucleotide reductase, Ssp1 that is a protein kinase involved in stress response pathway, and Crp79 that is required for mRNA export, in addition to Spi1, S. pombe Ran-homologue, and Nxt2, S. pombe homologue of Ntf2p. Consistent with the identification of those suppressors, lack of ScMog1p dislocates Opi3p from the nuclear membrane and all of Spmog1(ts) showed the nuclear accumulation of mRNA. Furthermore, SpMog1 was co-precipitated with Nxt2 and Cid13.