Fig. 1

Sup-46 encodes an RRM protein related to human MYEF2 and HNRNPM, and Drosophila RUMP. a SUP-46 has a predicted nuclear localization signal, three RRM domains, a glycine-rich low complexity (LC) region, and a MYEF2 motif within the LC region (see Fig. 1d for details of MYEF2 motif). Amino terminus is on the left. The predicted full-length wildtype (wt) or truncated mutant [sup-46(qa707-qa710)] proteins are shown. For the mutants, the aa (single letter code) at which the nonsense change (X) occurs is indicated in parentheses. The closest human (MYEF2 and HNRNPM) and Drosophila (RUMP) homologs are shown for comparison. b SUP-46::FLAG::GFP restores embryonic lethality in adult hermaphrodite gna-2(qa705) unc-55(e1170) sup-46(qa708) (assayed by Unc-55 phenotype). The presence of SUP-46::FLAG::GFP was determined by examining for GFP (green data points) or no GFP (black data points). Hatched line and error bars are the mean ± SD (n = 4 replicate experiments; 20 embryos/replicate). c Dendrogram showing the two most closely related human SUP-46 homologs, MYEF2 and HNRNPM. Dendrogram prepared using NCBI BLAST(102) and COBALT Constraint-based Multiple Alignment Tool [110]. Scale shows Grishin protein distance. d The MYEF2 motif “LPxGLxxIGMGLGxxGxPI/L/Vx” in MYEF2/HNRNPM proteins, derived using homologs from 61 invertebrate and vertebrate species, listed in Additional file 1: Table S8. Color code for aa: black – non-polar, green – polar, blue – basic, red – acidic