Efl1 K983R mutation leads to pleiotropic effects in mice. (A) Multiple sequence alignment of EFL1 proteins from representative species indicates that the murine EFL1 K983R mutation targets a highly conserved residue. Identical amino acids are indicated by a red box with white characters, similar amino acids are in red characters, and a blue frame represents similarity across groups. (B) Representative total cell lysates of mouse embryonic fibroblasts (MEFs) from wild-type (Efl1^+/+), heterozygous Efl1^+/K983R, and homozygous Efl1^{K983R /K983R} mice were immunoblotted to visualize EFL1 protein. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is used as a loading control. (C) Quantifications show the EFL1/glyceraldehyde-3-phosphate dehydrogenase ratio. (D) Representative polysome profiles of MEF extracts from Efl1^{K983R /K983R} (n = 4) and heterozygous Efl1^+/K983R (n = 9) mice compared with wild-type control (Efl1^+/+) (n = 9). (E) Quantification of the 60S:80S ribosomal subunit ratios is indicated as a bar chart (n ≥ 4). (F) Global protein translation rates in MEFs from Efl1^{K983R /K983R} and heterozygous Efl1^+/K983R mice compared with wild-type control (Efl1^+/+) (n = 6). EFL1 K983R mutation reduces body weight from 3 weeks of age (G), affecting the percentage of fat mass (H) and bone mass density (I) from 3 months of age. For all tests, P values are indicated.