Figure 1:
rsks-1(
gk185793) that causes the E255K change reliably extends C. elegans lifespan at 20C. (A) A schematic showing the changes caused by
rsks-1 mutant alleles tested in this study.
gk185793,
gk587386, and
gk902595 cause mutations in the 4th exon of
rsks-1 for resulting in E255K, P360S, and D370N changes, respectively.
tm1714 harbors a 484 base pair deletion and a three base pair (TTT) insertion at the 4th exon of
rsks-1. (B) The domain structure of RSKS-1/S6K protein in C. elegans. Amino acid (aa) numbers are shown at the bottom of the start and end residues of each domain. Kinase domain (83 aa - 344 aa), AGC-kinase C-terminal domain (345 aa - 415 aa), and predicted autoinhibitory motif (439 aa) are indicated. E255K is a point mutation in the kinase domain of RSKS-1. P360S and D370N mutations are in AGC-kinase C-terminal domain. (C) Three-dimensional structural modeling of worm RSKS-1. Mutation sites and the predicted autoinhibitory motif are painted as red. The E255 is located in the kinase domain (green), whereas P360 and D370 exist in the AGC-kinase C-terminal domain. (D) Alignment of amino acid sequences of human S6K, mouse S6K, Drosophila melanogaster (fly) dS6K, and C. elegans (worm) RSKS-1. A gray histogram represents the degree of amino acid conservation. Asterisks indicate residues that are completely conserved across species. Colons indicate any of the following amino acid residues that are strongly homologous: STA, NEQK, NHQK, NDEQ, QHRK, MILV, MILF, HY, and FYW. Periods indicate any of the following amino acid residues that are weakly homologous: CSA, ATV, SAG, STNK, STPA, SGND, SNDEQK, NDEQHK, NEQHRK, FVLIM, and HFY. (E-H) Pooled lifespan curves of
rsks-1(
gk185793) (E),
rsks-1(
gk587386) (F),
rsks-1(
tm1714) (G), and
rsks-1(
gk902595) (H) mutants compared with that of wild-type (WT: N2). (I) Statistical analysis of individual replicates of lifespan data. p-values were calculated using a log-rank (Mantel-Cox method) test. Biological replicates of the lifespan data were divided by dashed lines. S.E.M. represents the standard error of mean.