The Aspergillus nidulans IQGAP orthologue SepG is required for constriction of the contractile actomyosin ring.

In this research we report that the sepG1 mutation in Aspergillus nidulans resides in gene AN9463, which is predicted to encode an IQGAP orthologue. The genetic lesion is predicted to result in a G-to-R substitution at residue 1637 of the 1737-residue protein in a highly conserved region of the RasGAP-C-terminal (RGCT) domain. When grown at restrictive temperature, strains expressing the sepG (sepG1) allele are aseptate, with reduced colony growth and aberrantly formed conidiophores.