Table 4. Summary: Invertebrate modifiers of SMN loss of function.
Ce gene | Dm gene | Hs gene | Change/Affect Ce | Change/Affect Dm |
plst-1 | Fim | Plastin 3 (PLS3) | RNAi/Cmpx Gr, Enh Pump | Lof/Enh |
daf-4 | Wit | TGFβ receptor (BMPRII) | RNAi/Enh Pump | Lof/Enh |
kcnl-2 | SK | SK channel (KCNN3) | RNAi/Enh Gr, Sup Pump≠ | Lof/Enh |
nhr-25 | Usp | NHR LRH-1 (NR5A2) | RNAi/Sup Pump | OE/Enh |
uso-1 | p115 | Vesicle docking (USO1) | RNAi/Enh Gr | OE/Sup |
nhr-85 | Eip75B | NHR RevErb (NR1D2) | RNAi/Enh Gr | Lof/Enh |
atf-6 | Atf6 | Atf6 trans. factor (ATF6) | RNAi/Enh Gr | ?/Sup |
egl-15 | Btl | FGF receptor (FGFR3) | RNAi/Enh Gr | Lof/Enh |
ape-1 | CG18375 | p53 inhibition (PPP1R13) | RNAi/Enh Gr | ?/Enh |
nekl-3 | Nek2 | NIMA family kinase (NEK7) | RNAi/Enh Gr | OE/Sup |
atn-1 | Actinin | a-actinin (ACTN) | RNAi/Sup Gr | OE/Enh |
cash-1 | CG33172 | Striatin (STRN) | RNAi/Cmpx Gr | Lof/Enh |
dlc-1 | cut up | Dynein light chain (DYNLL2) | RNAi/Cmpx Gr | Lof/Sup |
ncbp-2 | CBC20 | Cap binding (CBP20) | RNAi/Enh Gr & Pump | Lof/Enh |
grk-2 | Gprk | GRK kinase (ADRBK1) | RNAi/Enh Gr & Pump | n.d. |
flp-4 | FMRF | Neuropeptide (NPFF) | RNAi/Enh Gr | Lof/Enh |
T02G5.3 | none | none | RNAi/Enh Gr, Sup Pump | n.d. |
The summary table is divided into three sections corresponding to potential Cesmn-1(lf) modifier genes originally identified in humans, Drosophila, or C. elegans (1 in Hs, 40 in Dm, and 4 in Ce, respectively). Species and gene names are listed in the first three columns. The change in gene expression due to Drosophila GAL4-driven transposon insertion lines or C. elegans RNAi knockdown is listed in columns 4 and 5; effect on Drosophila gene function is predicted based solely on transposon insertion sites in some cases. (RNAi: RNAi knockdown; Lof: loss of function; decreased function or antisense; OE: over-expression; ?: unclear; Enh: enhanced SMN loss of function defects; Sup: suppressed SMN loss of function defects, Cmpx: complex genetic interaction; not determined, n.d.). Column 4 includes the C. elegans assay revealing modifier activity (Gr: growth; Pump: pharyngeal pumping.) RNAi knockdown was sufficient to modify pumping rates for T02G5.3 and ncbp-2; mutant alleles of grk-2 exacerbated Cesmn-1(lf) pumping defects. flp-4 loss decreased Cesmn-1(lf) pumping rates in 4 out of 5 trials, but did not reach significance overall. Discordance between Drosophila and C. elegans results is indicated with ≠.